THE A NATO MY O F THE HUM AN EYE

AS I L L U ST RATE D "Y

E NL ARG E D STE RE O SCO PI C P H OT OG RAPH S

R H U ‘ HOM SON M E T R M . A "Y A . . . E , , , PROF E SSO R OF HUMAN ANATOMY IN TH E U NI"E RSITY OF O"F ORD

O"F O RD AT TH E CL ARE ND O N P RE SS "IO ' Q GY

H RY F ROWD E M . A. EN , P R E FAC E

To th e D elegates Of th e U n ivers ity Press I am greatly i n debted for th e gen erou s assi stan ce th ey h ave ren dere d in th e r du n of th p o ctio is work .

Th e Public h ardly realizes h ow much th e U n iversity does th rough th e agen cy of thi s D elegacy for th e en couragement o f s h arsh an d resear h s n e w th u su h h e mu h c ol ip c , i c i o t c lp c

r mun ra r r u h un e e tive wo k would emai n unp blis ed .

r W h tan t I am eat T . m O M . C esterman Museum ss s , y A i , gr ly oblige d for th e skill an d patien ce wh ich h e h as di splayed in c arryi n g out my i n stru ction s : with out his co - operation it wou ld h ave been well n igh impos sibl e for me t o h ave attain ed th e

r t presen t esul s .

h h k m n a r Mr E. S . I a e a s to an S e r em n s r t . v l o t y io D o t o ,

E fo r i aid in r t r f- h t W h n a M h s e s n h s ee s . . e it ll , . , vi i g p oo M A RT H U R T H O S ON .

O"F RD a I 1 1 2 O . n . f , 9 CO N T E N TS

INTRO DUCTION

CHAPTE R I

ANTERO - POSTERIOR SECTIONS OF TH E EYE

C HAPTER I I

DISSECTIONS OF THE EYE FROM TH E FRONT

C HAPTE R I I I

ANTERIOR H AL F OF TH E EYE SEEN FROM BEH IN D

CHAPTE R I"

C HAPTER "

POSTERIOR H AL F O F TH E EYE

"EY To PL ATES E RRATA

2 l 2 m m m to mm I o or m r ea d . 4 . , f . 3 .

P I 6 r NO 6 rea d No 6 a e rom oot o . . g 54 . f f , f 7 5

Th om s o n A n a tom o th e H u m a n E e , y f y

May 1 9 1 2

I N T R O D U C T I O N

TH E acc ompanying stere osc opic views of th e interior of the eye we re prepare d in illu s tration o f a c ou rse o f lectu res o n th e gros s a om th e e e i e t o th e a s ari for an t y Of y , del v red gradu te prep ng the h i e i of o o diplom a in Ophth alm ology Of t e Un v rs ty Oxf rd . They were s generally app re ciated th at it is h oped th eir pu blicatio n in th e p res en t fo rm may m ake th em acce ssible t o th o s e wh o wo uld n ot o th e rwise in e a o f th e u r in h ave an oppo rtunity of s e e g th m . M ny struct es the n e e are s o a a it is o o i e r o i a i huma y sm ll th t nly p ss bl , unde rd n ry c rcum a to o ain a i a o "ie of e ea of a en of low st nces , bt a s t sf ct ry w th m by m ns l s i u u a in o e i e a i a io i ow . o o a i o p er Th s s lly v lv s the r x m n t n by m n cul r v s n , an d c o ns eque ntly e n tails a lo ss o f that stereos c opic effe ct which is s o n eces sary t o dete rmin e their exact rel atio ns . With th e o bject of over o in is e th e re n i u ra ion we e re are in c m g th d fect , p se t ll st t s r p p d such a wa as t o e e th e er o o i ef e an d at th e s a e i e to y pres rv st e sc p c f ct , m t m provide for s u ch a m agnificatio n as would re nder clear m ost Of th e detail

e i In an i n s a a i im e r - s a e is o o ra e a d s red . m y t nces m ll t e c l ph t g ph d long s i e th e a a io s o a th e e ma o a ro i d prep r t n , th t stud nt y have s me pp x mate i n i n id ea of th e siz e of the structu res h e s viewi g . It s ot s u gges ted th at th e pres en t s erie s of "iews s h o uld b e a substitu te for the ex p erien ce gain e d by the actu al dis s ection Of hum an or oth e r m ammalian e es bu t w e one o i e s a o e r i ar u a y , h n c ns d r th t such , m r pa t cul ly h m n , m aterial is n ot easily o btainabl e in a s u fficie ntly fresh c o ndition to i a all th e e ai s s ru u re t h e a o a i a e d spl y d t l Of t ct , cc mp ny ng pl tes may s rve as a in e th e a re s re io s e a i o e u rem d r Of fe tu p v u ly x m ned , and pr v seful as a h andy means of refe re n c e whe n p e rmanent preparations or museum s e i n s a n i p c me re ot readily acces s ble . In mos t in stanc es th e sp e cim e ns from which th e ph otographs were taken we re re m ove d within fo ur h ou rs after d eath . Th ey were a n in % s o u ion of o o s s n o an d e h rde ed a 4 l t f rm l , ub eque tly fr zen th n c i r r e o e ut . e is e o s e e e a w e e The furth r d s ct n , wh n cess ry, e th n p rf rm d ,

an d e a io n s o o ra u e r i i . a was a en as the pr par t ph t g phed nd sp r t C re t k , far as os i to e imin a all s e i s w i a eare au an d p s ble , l te p c men h ch pp d f lty, o n ly th os e which p re se rve d the n atu ral form an d te n sio n of th e gl o be we re i i e i a was a n o u ut l zed . Ev ry p o ss bl e c re t ke t avoid d ou btf l e a s an d th e a o i o f e ime n s in s o far at s as i x mple , m j r ty the sp c , lea t the r a or a s are o n ern e ma be re ar e as affo i an a roxi m j p rt c c d , y g d d rd ng pp ma e a u ra e r n f i n o r a o i ion o e t ly cc t epres e ntatio o th e r m l c nd t . D ubtl ss the m ore d elicate stru ctu res u n d ergo some alte ration in th e h arde ning 0 0 5 0 o 3 “ f I NTRODUCTION

' i ' p rOcess; b ut the éa‘me may be s aid of n early all th e o ther meth o ds of or n i w preparatio n that have be e n sugges te d . Opp tu ty as als o tak e n t o e o i a e a es of o e e an d o o ra s of secur s me typ c l x mpl f etal y s , ph t g ph a few o f th e s e h ave b ee n in cl u ded with the o bj e ct of illustrating i structu res and relatio n s of p ractical n teres t . i mu ma earn e om th e is e ion of a r e e Wh lst ch y be l d fr d s ct f esh y , such a of th e i or ox e t th e s e i a e e in e s e as th t p g , y tud nt w ll find th t v n th case s a p revio u s h ardening of th e specim e n s employe d will be of service in assisting him to Obtain a m ore s atis factory view of the u re i Th e ri e ri io i in th e u ee i str ctu s nvo lved . b ef d sc pt n g ven s cc d ng ch apte rs lays n o claim t o be a c o mplete systematic acc o u n t of the i e o e rn e r e or ore i or a e ai s in t ssu s c nc d , but me ely s ts f th the m mp t nt d t l e i arran em n s u as ma be r a i on s ra e in ion th r g e t , ch y e d ly dem t t d the sect s — o r dis se ctio n s e mployed d e tails which any student may verify for i e e o in i e o r i i a e o Fo r i re o th e h ms lf by mpl y g l k s m l r m th ds . th s as n ph otograph s h ave bee n gro up e d acc ordin g to th e meth o d of sectio n e o o r as i s a i e o f i fer n a e in a i ion so a mpl yed , llu tr t v d f e t st g s d ssect , th t befo re p ro cee ding to th eir examin atio n th e studen t wo uld do well t o rend e r himself familiar with th e systematic acc ou n t of th e stru ctu re of th e e e i in an of th e u r y g ven y c r ent textb oo ks .

Th e o o ra s a e e n mo u n e o n ar s a ar i s o ph t g ph h v b e t d c ds Of t nd d s ze , that th ey will fit any of the n u mero u s stereo sc opes already on the a m rket . C HAPTE R I

- ANTERO - POSTE RIO R SECTIO NS OF THE EYE

TH Is section includes th os e spe cim e ns which h ave bee n divid e d

- h e a e f e i ante ro p o sterio rly . T pl n o the s ct o n may e ither be vertical or

o ri o a o r o s i i u e . is n ot a a o s i e to sa h z nt l , p s bly Obl q It lw ys p s bl y exactly h ow th e io n was a e as in o e i an n o o was a of sect m d , s m nst ces n te t ken

th e o rie ntatio n of the eye . — re a a io n e re e o u e No s . 1 1 8 i e an The p p r t s h r pr d c d , , g v the student oppo rtunity o f stu dying t h e ge n eral arrangement of th e parts within o an d n him to ami ia i i s wi th e i o i io of the gl be , e able f l r ze h m elf th d sp s t n

iffere a i o its o s . e e a the d nt l yers wh ch f rm c at Of th s l tter, the external or s clero ti c coa t or s clera is s ee n to fo rm abou t of the circum r of th e o e in re it is i e i e e fe ence gl be . B h d , whe p erc d by the Opt c n rv , i th e o i e o e ri of th e e e is i e s it a u th s , pr tect v c v ng y , th ck t ; here me s res r a i it a f I mm . o little over ; it gradu ally thins unt l re ch es th e regio n o

- i r i u 0 in . e io t o a o r e re t a a s a o . s the equ t , wh ver ge b t 5 mm th cknes Ant r is ow er it a ai e o es o r owi t o its sio wi th , h ev , g n b c m st ute ng fu n th the e o n of i er io n of th e re i e s e it a o t nd s ns t ct muscl , wher me sures ab ut 0 m d r it es m . i n e s w i is ai ain e an i a i 7 , a th ck s h ch m nt d nc e sed unt l reach th - i r m in e ro o n ea io n w re o n an a a t a e 0 m . scle c r l junct , he ver ge me su s 9 i n th ck es s . An te rio rly th e re is a large ope n ing in this coat i n which th e c ornea

’ is e cor nea l a ertu re ora t z men sclerae a n er us . bedd d , the p (f ) The edges of is a e in a u are s o i to o er th p rture , the d lt , bevelled as sl ghtly v lap the circ u mfe rence o f the c ornea ; the ave rage diam eter b e twe en the extern al in s f h 1 0 marg o t e bevelle d e dge meas u res a little over I O mm . ( 5 i wh lst the Width between the inner or p o sterior edges is ab out I I mm . o to r i ri i se e Ab ut 3 mm . the inner s id e of the ve t cal me d an ( nd ra is i os . a i s N . ow o i o i I , I mm bel the h r z ntal mer d an , the cle p erced os io t h e o i e r is o tic ora men o the sclera p ter rly by pt c n ve . Th , the p f f ' ora men o tzcum s cler ae is n a owe in r w e it (f p ) , rr r te nally, h re measures in r a i e o 2 . ia e e n e rn a w its i is a mm d m t , th xte lly, here w dth l ttl ver

mm A wi be s e n h o o a s No s . . s e o an in s e io of t e 3 ll fr m p ct n ph t gr ph ( I , 2 6 th e o r a e rs th e era are e e on to t h e , 3, 4 , 5, , ute l y Of scl r flect d u a ea o i e e i i n e a e as s a os s d r l sh th Of the pt c n rv , wh lst the n r l y r p se cr ' th e n ar ow of th e o o i th e la mina cr zbrosa u r est part f ramen , f rm ng , th s i app earing t o pin ch u p th e nerve as it p as ses th rough the open ng . N s 6 s o r h t r s o f th e o i e o . ea ow h e e I , 4 , 5 , h w ve y cl rly fib pt c n rve u n r o a an e at i oi for i in th e a i a e s de g ch g th s p nt, w th l m n the nerv fibre 8 ANTERO - POSTERIOR SECTION S OF TH E EYE

are de void of the m e dullated sheath which th ey acqui re extern al to it . This ch ange in structu re is in dicated by the differe nce in colour s o o clearly sh own in th e ph ot graph s . 1 h e in s u a e of th e e a is o s e th e o e In No . 3 t ner rf c scl r exp d by c mpl te e o a of on s of th e e a an o era io w i h as i e r m v l the c tent ey b ll , p t n h ch nclud d stripping away fro m the inn er s urfac e of the s clera both t he nervou s nd a a — Chor ioid— is s e a ro a vascular c o ts . The l tter the p rated f m the i n n r a e of e th e er ichor ioida l s a e o i e surf c the scl ra by p p c , thr ugh wh ch a o th e o e io i ia ar ie an d th e i ia n e e th e p ss f rward p st r r C l ry ter s C l ry rv s , c o urs es of which are indicate d by the lighter tracts r eveale d u pon the i n i e e r a e of ra th e o ou of i is i ner p gm nt d su f c the scle , c l r wh ch ma nly du e t o th e ai o f la mi na usca a e a e a i e rem ns the f , fin ly tr b cul r p gm nted e e layer which bridges across th e p erich orioidal spac . Wh n the o ioi is o a a i a e u a is s s i in o two a e s Ch r d t rn w y th s tr b c l r t ue pl ts t l y r , o n e of w i ain s a ere t o th e i n er s r a e th e s ra as h ch rem dh nt n u f c Of cle , h as u e e ai i th e o er i in t o th e o e j st b en xpl ned , wh lst th st ll cl gs ut r s u rface of th e sep arated Ch orioid forming th e n o n - vascu l ar l ayer which is o fte ntimes r e ferred to as th e la mina s uprachombida lis . The a erio a of inn a e a i o es o s to nt r p rt the er surf ce Of the scl r , wh ch c rr p nd ' o i io of th e or bi culus cilia ms an d th e cilia r bod is u i the p s t n y y, m ch l ghter in c olo ur owing to th e abs ence of pigment : a d ark e r z on e usu ally in di a e o i io n f m s t th n as e th e er c t s the p s t o the o er ra a . On e in er p ct Of scl a i e o n i o f vor ticose veins om on ou in m the Obl qu pe ngs the , c m ly f r nu ber ,

an u e an d a o air can u a be e 2 o r . i pp r l wer p , us lly s en 3 mm beh nd the e a o at s o e i i ia a e o n ei e i e of th e e i a e . qu t r, m d st nc th r s d v rt c l m r d n th e oe a e e it i be e en a e Nos . 1 1 6 1 In f t l y s figur d ( 5, , 7 , w ll s th t in th e n ewb orn child th e scl era c onstit u tes 4/5 of th e circumference Of the o e in a of in th a r i as e a u . is as wi o e s gl b ste d d lt Th , ll be sh wn l t , due t th o e propo rtio n at ely great e r siz e of th e c orn ea in th e fo e tu s . The sclera d o es n ot display th e variatio n s in thick n es s ch aracteristic of the a u an d en to be o or ion a e i e in ro w ere it re ei e d lt t ds pr p t t ly th ck r f nt , h c v s orn a wi i th e r r t th e wa in o a e e e an eriu s . e oo the c e th n f m n scl ra t He , , y which the corn e a is embedd e d diffe rs fro m th at al ready re ferred to in th e a u for th e e o f is o en i are n ot e e as in th e u d lt, dges th p ng b vell d f lly ow e e ra e oo e s o a e IS i o r n o iffe e gr n y , but th r gr v d , th t ther l ttle d r nce b e tween t h e m easu re m e nts acro ss th e exte rn al an d intern al margin s of a er u e r a e i o e o i t o oin in er the p t r , the g e t st w dth c rr sp nd ng a p t t e ia e e wee n th e two mar i F or u r er ai s o n e r in m d t b t g n s . f th det l c c n g the

e a s ee . 0 an d scl r pp 4 53. Th e corn ea in the adult forms a littl e m ore th an o f th e circu m re n o f th e o e in s e io In i n es th e o n ea a e ra s fe ce gl b ct n . th ck s c r v ge

- o 0 mm . for its e ra r i at it s eri er th e ra ia ab ut 95 c nt l pa t , wh lst p ph y d l

i is - r a e e i reas e to m m o m 1 0 to 1 1 . o d m t r nc d m . It eas ures fr 5 mm f m i to i an d is e i in th e ra men s clerae a n ter i us in c s de s de , bedd d w th fo su h ANTERO - POSTERIOR S ECTION S OF TH E EYE 9 a way that th e bevelle d edge of th at apertu re overlap s it slightly a o its i ere e w er th e i of e a o a r und c rcumf nc , h e t ssues the scl r and c rne are e blend d . As a result of the differe nc e s in the lengths of the radii of the circles o f i th e o a and e a or ar rn a o a r a wh ch c rne scl r f m cs , the exte l c rne l su f ce proj e cts b eyo nd a ch ord p ass in g thro ugh its circu mferencq h ere it u nit es with th e sclera e xte rn ally (s ulcus s clerae exter n a s) t o the e xtent o n an a e n i o t o - 2 i n i a e of 2 mm . a v r g 5 , r g ng fr m 3 the spec mens e a i x m ned . wi to e e of i es of ora men s clerae a n ter i us O ng the b v l the s d the f , the ar a f h o t e orn ea w ie e rom wi i is a ou 1 . i r in e c , hen v w d f th n , b t mm w de its ia n a e e na d meter th a th t xpo s ed ext r lly . Th e In n e r s urface of th e c o rn ea n ot o nly forms p art o f the arc of a a e ir e a o f e a u r a th e re sm ll r c cl than th t the ext rn l s f ce , but cent s Of the t wo ir do n ot oin i e a of ma er i e in e io t o c cles c c d , th t the s ll c rcl ly g ant r r th e c entre of the larger Circl e by a dis tance equ al to th at of the cen tral i n es a s a o e i th ck s Of the c o rn ea . The me sure t ken fr m the sp c mens e xamin e d yield an average radial length fo r th e curve of th e e xter nal s a e of 8 - m i s f r in n e m n in 0 o 8 . o o 1 . t urf c 4 . , ra g g fr m mm mm , wh l t the r

s u r a e ra i f th 68 r in r . o e u r e a e a e . o f c the d us c v v r g s mm , ang g f m 9 mm o 6 t mm . In this way the inc reas e d thickn e ss Of the c ornea at its p eriph e ry is a ou n e for bu t o e a an em e is e a w ere i cc t d , s m rr g nt n cess ry h by the th cker c o rn eal margin may acc o mmodate its e lf to the b evelled e dge o f the orn a a er u re of th e s e r is is ro i e for th e rou n i c e l p t cl a . Th p v d d by d ng O ff o f th e in er orn ea ma i w e r it e o on wi n c l rg n , h e b c mes c fluent th the i n er s r a e of th e era ar i n s o a in a e of or i i th e n u f c scl l m g , th t pl c f m ng w th a er a n i orm owi e it a s a e of its o er l tt u f fl ng curv , m ke , by the bruptn ss v an a u u s or ro o e at oin ere it e o es e e i h g, s lc , g v , the p t wh b c m bl nd d w th s era i s i n 1 1 i er in u e b in . . s . ca e we s n os the cl l t s Th s ll ee N 4 , It h e , n e i o r oo of th e ra io an a th e oo s o o e ie the ghb u h d filt t n gle , th t gr ve f rm d l s , ' t o i n i wh ch the am e s u lcus circa la ms cor n eae h as bee n appl e d . The fu rth er c on sid eratio n of this arrangement is p ostpon ed u n til th e gross ana o of th e i a i it ra o a e i s on si r s ee . t my filt t n ngl c de ed ( p me nwh le , may be s ufficie nt t o n ote that th e pre se n c e of this groove is again Clearly ’ e o s ra er th i i e in Nos . 1 2 a an d 1 b ere in o e d m n t t d ( ) 3 ( ) , wh the f rm r s h as ee re o e w i s in th e a e r th e w o e of u ea ra h as b n m v d , h l t l tt h l the v l t ct en r u e i be st ippe d Off from th e in n er su rfac e Of th e sclera . A f rth r v ew o f u s is a s o ain e in No w ere th e in r s r a es o f the sulc l Obt d . 47 , h ne u f c the orn ea and s era are i a e c cl d spl y d .

th - o of In e full time fo etu s (No . th e c orn e a am o unts to ab ut the circumfere n c e of th e glob e o n s e ction it s tran svers e diam ete r m easu res i e a o mm . in th e s e imen s e amin so a e e is om ara b ut p c x ed , th t th r c p t v ly l ittle in creas e in its growth re qu is ite to reach the adu lt p roportions . It 1 0 ANTE RO - POSTERI O R SECTION S OF TH E EYE

o o a in a in th e i o f th e o e e i is f ll ws , then , th t the cre se s ze gl b aft r b rth mainly du e t o the expansio n of the scle ral part o f the eyeball an d its h f n co nte n ts . At birth t e thicknes s o the c orn ea is o t o n ly propor tio natel a o a s o e a e a th e i of o ea y, but ls b lut ly gre t r th n th ckness the c rn

- i n a . In th e u i o u it me r 1 0 . at en e the dult f ll t me f et s asu es 4 mm the c tr , 3— ’ - i - o 1 . at a 6 o and inc reases t 60 mm the per phery . In m nths foet u s

- - the or e o in ea u e 1 0 . an d 1 0 r c r sp nd g m s rements w re 3 mm 4 mm . es pe c l Th e a n in i o n is i n th e s e i tive y. m n er wh ch the c r ea bedded cl ra w thin the fora men s cler a e a n ter i us also diffe rs from th at which is ch aracte ris tic of the adult : wh ereas in the latter the co rnea is set within the b eve lle d e e e a it a a s in th e o t o n in a ro o e dg Of the scl r , ppe r f etus be su k g v wi in era a th e e i o it to s i th the scl l subst nce , edg s Of wh ch verlap a l ght n i F or r ai e xte nt both in fro nt a d beh nd . fu ther det ls concerning the co rn e a s ee p . 4 1 . u v eal tr a ct or v a s cu la r c o a t i o is Ch ori oi d The . Th s c mpr es the , th e ilia r b o d and th e i ri s and o i th e i e oa of th e C y y, , c nst tutes m ddl c t eyebaH.

Th e Ch ori oi d (choroid) . This vasc u lar laye r Cl othe s the inn e r sur Of th e s era as o w r as th e or a ser ra ta s a o e e e face cl far f r a d , the c ll p d dg ’ Of th e n e rvo us laye r Of the retina. In fron t of this th e chor ioia is con tinu o u s wi th e Cilia r bod u ure w i rea e a e rior t o n ea th y y , a str ct h ch ch s nt ly r

in e n a s clero- cor neal a n otion at w i oin it o e o i o s the t r l j , h ch p t bec m s c nt nu u th i r Th e i r wi ai e o s a e e is . e s a e th the curt n Of the aqu u Ch mb r, nn urf c of i i o e ior t o o ra e r i i a oo ia the C l ary b dy ant r the s r ata exh b ts sm th , str ted a ea a orbiculus cilia r is i is e a in o n o pp r nce , the , wh ch r pl ced fr t by numer us o e ro es e Cilia r r ocesses th e ou a rio e mi i f ld d p c s s , the y p , r nded nte r xtre t es of which project behind the i r is an d are directe d inwards toward s the ir u e r n o f s ro w i s a a an i e c c mf e ce the len , f m h ch they are ep r ted by nt rval

u n n n r a o . (the ci r cumlental spa ce) meas ri g o a ave age abo ut 1 mm . cr ss h as ee s ai o u i e th e ora s e ra a ma th e a erio As b n d , the tl n Of r t rks nt r ’ h ch r Th e osi io n of is a ie o n i e limit of t e o ioia proper . p t th edge v r s c s d r a in iff n an d in iffer a s of its i u m e e e ro bly d e re t eye s d ent p rt C rc f r nc . F m measu re men ts take n o n my own specimens I fin d th at the ora serrata lie s

- e in exter n a l sclera- corneal unction on an average ab out 6 2 mm . b h d the j (su lcus sclera e ex t er n n s) As th e Ch orioid lie s within th e sclera it is s e parated fro m it by the i o io i a e a s a w i as a a es ri e is per ch r d l lymph spac , p ce h ch , lre dy d c b d , s t o be o e u th e a is s u e th e a i a u een br k n p by trabecul r t Of l m n f sca , i u ni e s o ri wh ch t the Ch oid t o the s cl era . Owing to rough ha n dlin g or ine a i ie in r e in o e the o ioi e n to qu l t s the ha d n g pr c ss , Ch r d has a tend cy a a o the i ne u r a e o f s e ra in w i a th e a i sep r te fr m n r s f c the cl , h ch c se l m na u is e i e r e o r o i o two a e r th e o of i f sca th str tched t rn nt l y s , uter wh ch adh e re s to the scl e ra and imparts t o it its brown pigm ented appear a i th e i n e i e ai a to th e a ar o ioi nce , wh lst n r st ll r m ns att ched v scul Ch r d , ANTERO - POSTER IOR SECTION S O F TH E EYE 1 1

co nstitu ting wh at is Often d e scrib e d as the per i or sup ra chor ioida l a e th e e e w i i s u f a ea a to membr n , pr senc Of h ch g ve the fl fy pp r nce the o ri i oute r s urface of the s eparate d ch o d . i th e o a N e a ara e s e n o e o o s . Thes ppe nc may be se n s m Of ph t gr phs ( 7 , 8 I O 1 2 w e a a ia s e a io o f th e orioi o th e ra , , , h re p rt l par t n ch d fr m scle reveals in so me i n stanc es th e fi n ely stretched ope n tiss u e oflt he la mina In e io a o n th e o i e th e a e e o f th e fusca . the r g n r u d pt c nerv dh renc o ioi to the e is or i i a owi to th e as a e of ch r d scl ra m e nt m te , ng p s g the o os e io i ia ar i o o n e o to th e o er s o r sh rt p t r r C l ry ter es fr m c at th . A h t distan ce be hind the equ ato r th e emerge n c e of the fo u r or five great or ticose vei ns ore or e u a i e a s a ar on e i wa to v at m less r g l r nt rv l p t, th r y i r th e e a e to i o e e orioi a and e a oa p e ce scl r , serv s l nk t g th r the ch d l scl r l c ts e Th e i n r a of th e orioi is o f co n m ore intimat ly . n e l yer ch d f rmed o

d n ed o e i i e a th e la mina basa lis o r la min vitr a e s c nn ct ve t ssu c lled a e . i i in on a i e n a wi i a of th e e i a and Th s l es c t ct nt r lly th the p gment l yer r t n , s o intimate is th e c o nnexion th at if an attempt be m ad e t o separate the re tin a from the ch o rioid the pigment laye r of the retin a almost i a ia ain a e e n to th e in e a e of th e o rioi a cir nv r bly rem s dh r t n r surf c ch d , cums tance which explain s why th at pigm en ted laye r was fo rme rly a as on e of o i e of th e mi oa ore its u e reg rded the c nst tu nts ddle c t, bef tr i n i a e was a e a ow e e of its e o m e s g fic nc reve l d by kn l dg d vel p nt . It is a m atter o f great difficulty in the preparation Of eyes for d e m o nstratio n o es to es e i a u io of e e e ra a e rs in th e purp s pr rve nt ct the n n thes s v l l y , and a e are u e o am es N 0 & 6 1 . i n o o os . c ph t gr phs th re n m r us ex pl ( 3, 4 , 5 , , , ) which th e retin a is s ep arate d fro m the Ch o rioid bu t n ote th at in every a e th e ra e re i a o ri i its e o s e e n a ea s c s sepa t d t n , c mp s ng n rv u lem ts, pp r w i o in t o th e a a its i e a e r s i r ain s i e to h te , w g f ct th t p gm nt l y t ll em un t d t h e o ioi th e in of a a e o th e re in a o rre on i ch r d , l e cle v g thr ugh t c sp d ng to the cleft which in early developme n t s eparates th e ou ter from th e r a f th n inn e l yer o e s eco dary optic vesicle . Betwee n th e l amin a basalis in tern ally an d th e lamina suprach o rioidea

e r a th e re of o ioi on s is of a on e i e - i ext n lly, structu the ch r d c ts c n ct v t ssue

o a o i i m oo - an d a o i e o o f str m , c nta n ng any bl d vessels c ns derabl am unt i i re io e i s its oo s o t p gment . As th s g n d r ve bl d upply fro m the sh r o s e io r i iar ar eries it o ow a o ioi is i er e i p t r C l y t , f ll s th t the Ch r d th ck b h nd

h e i r - i i an in ro t n e a in o 0 1 . n th e o a o th f nt , th ck ss r ng g f m mm reg n r und

n r n f i - m in n ei u r f th the e t a c e o the opt c n e rve to 0 06 m . the ghb o h o od o e i i its a s s e o f th e o ioi r s ora s e rrata . W th n sub st nc e the ve ls ch r d a e o an a e s o e er a a e la mina arr ged th t the larg r ve sels f rm an xt n l l y r, the vasculosa i in e i e a a er a e u of fin e i arie , wh lst a th n r nt rn l l y , m d p cap ll s ,

h chor io - ca ill r is is ri e o e rn a in th e co nstitutes t e p a . D t but d m st ext lly

lamina vas culos a are th e wh orl - like groups o f th e tribu tarie s o f th e vorticose veins an a an w i is a i is a as i n o o , rr gement h ch re d ly d pl yed , ph t No 6 w e e t h e orioi h as e s i e wa rom graph . 5, h r ch d be n tr pp d a y f the 12 ANTE RO - POSTERIO R SECTION S OF TH E EYE

s o its o s a . N 1 1 and. 1 2 clera so as to exp se uter urf ce In os . the inn er o r retinal s u rfac e of th e ch orioid is expo s e d by th e rem oval of th e n ervou s laye rs o f th e retin a ; h e re th e pigm en te d re tin al laye r is still in n o n i th e orioi i m ost part i c tact w th ch d . The l ghter t racts which are s ee n o n th e s urfac e of th e ch orioid co rre spon d t o areas wh e re th e pig m en t layer h as t o a greater ext e nt b ee n re m oved owin g t o its m o re i ima e a e re e t o th e n ou a of i a w i in orre nt t dh nc erv s l yers the ret n , h ch c s on din i u a ion s we re o in o o s o u e ei er th e p g s t t thr wn t f ld , pr d c d th by irregu lar c ontraction o f that membran e u n d er th e influ e n ce o f harden ing

- a n or o o e a . ge ts, by p st m rt m Ch nges

th e u - i o e a e i i in O o ioi is In f ll t me f t l eye xh b ted N . 5 , the Ch r d c a a e i e a rea er o or io a e i es s an d is o r mar h r ct r z d by g t pr p t n t th ckn , als e k a e in its a e rio imi e ermin th e o i io o f o ra bl that nt r l t , d t ed by p s t n the i i F s a e u u r e r orwa a n a u . or serrata, pl c d m ch f th f rd th n the d lt further d ai s o n e in th e r i 1 an d o io s e e . et l c c rn g ch d pp 4 54 . In front o f th e ora s errata th e middle coa t or u veal tra ct of the eye e en o war s to r a r io n of th e e ro - o rn ea u io rom xt ds f r d e ch the eg scl c l j nct n , f it a ses i r h i r which p s nwa d s t o form t e is . The Ci li a ry b ody is th at part of it which stre tch e s fro m th e ora s er

h in - n io Th e in n e s u r a o f is rata to t e te rn al s cle ro c o rneal j u ct n . r f ce th i Th e os erio a a is e i m e an d is i i i e o two ar . re d eply p g ent d , d v s bl nt p ts p t r, a e orbiculus cilia r is ie im e ia in ro n o f ora a a c ll d the , l s m d tely f t the serr t , 6 m rom e ore a an d fo rm s a z o n e me asurin g on an average 3 m . f b f b ck

- m in in i i u a as . r d m . a wi a ran e e we n mm . an w ds , th g b t e 4 3 5 d v d l c es i o re n s a s oo ee i en a eara i a in Th s z ne p se t m th d ply p gm ted pp nce , d spl y g a radial s triatio n du e t o th e arrange m en t o f th e ves sels which lie within its u s an e for e e th e orioi i i it is o i o o e s b t c , h r Ch d , w th wh ch c nt nu us p st

riorl o e its o rio - a i ar a er an d th e es s e s of th e a u a y, l s s Ch C p ll y l y , v l v sc l r lamina rea ran in e m e e in ara e u n es i are o n e , r g g th s lv s p ll l b dl wh ch c nect d in ron wi th e Ci iar ro s s es i e ri e t o t h e s ria io n aforemen f t th l y p ce , g v s t t i e re er is th e in n er tio ned. Th e o er on s i e n o f th e orio th c t tu ts ch d h p s t , a a e m ran e e in on in u e orwar wi th e i n a er of th e b s l m b b g c t d f d , th p gme t l y

retin a ove rlyin g it an d clo s ely adh e re nt t o its in n e r su rfac e . Be it rememb e red th at t h e n ervous l ayer of th e retin a d oe s n ot in ron o f th o ra rra a extend f t e se t . Th e anterior p art o f the in n e r su rface Of th e Ciliary b o dy is m arke d f a r by a s erie s of alte rnating ridge s an d fu rro ws lik e th e fold s o uff . ’ o e er o s i u e th e cor on a ra a ia ta o r coron a cilia r is i is These t g th c n t t t , , wh ch m a e u of o 6 t o 8 cilia r r ocesses th e a e a u e ein d p fr m 7 4 y p , v r ge n mb r b g a ou 6 or b t 7 77 .

n rio r i i s of ese cilia r rocesses are u - a an d The a te extrem t e th yp Cl b sh ped , o e in ar e i th e iris o ar s th e ir u m e e n e of th e e n pr j ct w ds, b h nd , t w d c c f r c l s , o i e are s e ara a aria e i er a th e cir cu mlen ta l fr m wh ch th y p ted by v bl nt v l , a ce i m a r n n mm O n e i iona s e io s e o a a e a e 1 . p , wh ch su es v r g m r d l ct n ANTERO - POSTE RIO R SECTION S OF TH E EYE 1 3

ea ri or in s a e ir e e n a su r a e ei thes e pro cesses app r py f m h pe , th xt r l f c b ng i r in er s u r a e th e s a ro w i owe e d re cte d towa ds the n f c Of cler , f m h ch , h v r, r a th e cilia r m uscle a o e i o r an o i u e they a e s epar ted by y , n th r mp t t c nst t nt f t i iar o s are u n e u a i n eir is o i o h e Ciliary b ody . The C l y pr cesse q l th d p s ' tion their l e ngth fro m th e point where th ey aris e from th e o rbiculus to e emi easu res o n an a e a their blu n t rou nded xtr ty , m v r ge but

ar n t all s a e i e an d n ot n n th e oro i a s they e o the m s z , u freque tly c na d spl y an arrangeme nt i n which the large an d small pro c esses appear to alte r Not u o o es e e i m e o s nate with each oth er . nc mm nly, th de ply p g ent d f ld a a a on i as if o th e exhibit a light er appe r nce l g the r edges , just s me Of ff pigment had b e e n ru bb ed o . t o e si of th e i ia o e o i i Lying o the ut r de C l ry pr cess s , and c nst tut ng i i r o is th e cilia i muscle i e a th e i s th e a v . is qu t h lf th cknes Of C l y b dy , g Th u s i i e i o t wo a s T co n sists of a z on e o f s m ooth m cle d v d d nt p rt . h e

e a or io th e fibrae m i io a of u e is w e - a e ext rn l p t n , er d n les Br ck , edg sh p d th e edge o f the we dge c orre sp o nds t o the attachment of the muscle — to the an n ular ligament at the in tern al s clerO c o rneal junctio n ; from i oi its re a a ar in a ri io a i io to be ost th s p nt fib s p ss b ckw ds me d n l d rect n , l in th e substance of the Ciliary pro c es s es an d t h e o ute r s urface of the orbi culu s Th e e e a r a of is r of th e is e o e en . xt rn l su f ce th pa t muscle xp s d wh th e i iar o is o n awa om th e i s a e th e a and C l y b dy t r y fr nner urf c Of scler , iffer o th e e of th e ea ra its i o ou as ma d s fr m r st uv l t ct by l ghter grey c l r, y 20 26 an d 6 i to th e i i f s een in o o a Nos . . o be ph t gr phs , 5 Ly ng nner s de

th e i of th e e e o e th e o - io e r an d co r summ t w dg f rm d by ab ve ment n d fib es , re s ponding to the b ase s Of th e free projecting ext re mities of the Ciliary o as as to th e a a me of th e i of i i pr cesses , well tt ch nt per phery the r s , i s a grou p of fibres o f varyi ng degre e s o f thickness arrange d circum all n i u i es of u er F r fe ren ti y ; th e se co st t te the c rcular fibr M ll . o further n n th e 6 an d 2 details co cerni g e Ciliary b o dy s e pp . 3 4 . Overlying th e in n er s u rface of the Ciliary pro cess are s een certain i r i i o wi i a e s a e . e a del cate l y r wh ch nt mately c nnected th them Thes l yers , which separate toward s the an te rior extremity of th e Ciliary process e s in o two o or s is i a in ae ri e a o i e e en t m re les d t nct l m , b dg cr ss the nt rval betw th e s of i iar ro e an d th e i u of e end the C l y p cess s c rc mference the l ns , and o zonule o inn o r s us ensor a a ra tus of e f rm the f Z , the p y pp the l ns . They wi be i e in rea e e ai a e eanw i ll descr b d g t r d t l here ft r (p . 37) m h le they are e io e n ow e a s e e w e in o o ra N 8 n os . a d m nt n d b c u th y are ell se n ph t g phs 9 , in which it cl early app ears that th ey form a partition which s eparate s u us cha mber in ro n ro th e vitr ous e i the a q eo f t f m e b h nd .

In th e s am e ph otographs th e s o - called ca na l of P etit is displaye d as in e a o in e io i s o i m e of th the t rv l , sh wn s ct n , wh ch urr unds the c rcu f rence e s ee n io and o rior e s of th e o e of len betw the anter r p ste fibr z nul Zinn . Th iri s 1 2 8 and in a me i i n i f e No s . o a o o e e ( , , 3, 4 , r d l sect n the y , a e a i e a i a e u rin n an a ra 1 i a s o 1 . n ia e pp rs l k d phr gm , m a g ve ge mm d met r, 1 4 ANTERO - POSTERIO R SECTION S OF TH E EYE

a e i i a e ou a e r its i e p l c d w th n the qu s ch mb . By c rcumf re nce it is c ontinu ous i th e r of th e a ra an d s i w th est uve l t ct , blend w th the tissu e immediately

i n ro n of ore ar of th e n e emi i s of i ia o f t the f p t blu t xtr t e the C l ry pr cesses ,

i e ia e t o th e n er - a nd mm d t ly in side of the summit of the we dge sh ape d a of i ia e the ir a of i l m ss the C l ry muscl , c cul r fibres wh ch ie j u st external d e i it a a t o an s . , b h nd , tt chment

o i a a is th e i n s of th e ir N te that th s tt chment th n e t part is . I find its

a a i in th e s e im at i o is 0 - 2 it n ver ge th ckness p c ens my d sp sal mm . ; te ds t o becom e thin n e r when t h e iris is stretched d uring c ontraction o f the

i and is i e th e i is i . r it s o b p up l , th cker wh n pup l d lated Furthe , h uld e O e e a is th e a a e e of i i is e i bs rv d th t th , tt ched dg the r s , turn d sl ghtly b ack a to n wi th e or a of th e i iar o s s o a th e w rds ble d th f e p rts C l y pr ce ses , th t i e etwe e e two o r or on t o th e nt rval b en th s structures, what c resp ds era en sio of oster ior ca mer a a ueous chamber i a lat l ext n the p Of the q , d spl ys in sectio n th e appearance of curving ro und th e extremities Of th e

Ciliary pro cess e s . This will of c ou rse be subject t o m odification acco rd i f iri ing t o the te ns on o the s . os i a e th e s io a o u il In m t nst nc s ect n has p ssed thr ugh the p p , the wi w i wi a o i t o its a of o a io dth Of h ch ll vary cc rd ng st te c ntr ct n . The circumferen ce of the pupil is bevelled at the exp en s e of its anterio r

r in s o a it i a a i - a e on s i n Th o . e ma g , th t d spl ys ch sel sh p d edge ect thin r i o e e is n ot a an d ea cu t bu t is n e e a o i ma g n , h w v r, sh rp cl n , fi ly cr n ted w ng t o th e disp ositio n of the minute folds which are arran ged radially on the r s r a e of i i o e to th e i poste ior u f c the r s cl s pup llary edge . The body o f h e i is wi a in i a o i to its a of o ra i t r ll v ry th ckness cc rd ng st te c nt ct on .

i a i i a e i it ma a 0 - in i i W th w dely d l t d pup l y me sure 75 th ckness, wh lst

a o n ra e i it ma be t o 0 - ri with c t ct d pup l y reduced 3 mm . The poste or u a u u a i a s an o i o in i a erio s rf ce s lly d spl y evenly fl w ng utl e , wh lst the nt r s fa e e i i a ri of o an d e s io ar i r en th e ur c xh b ts se es f lds d pre s ns , p t cula ly wh i a e p upil is d l t d . Th e e a ion o f th e i ri to a ueous cha mber can n ow ie r l t s the q be stud d . er e as a a i io n w i i i e a i i o two a er It s v s p rt t h ch subd v d s th t cav ty nt ch mb s , a n an e rior an d o rio w i lie r e i in ro n of an d in t p ste r, h ch esp ct vely f t beh d t h e i is an d w i o n i a e e wi ea o er o r , h ch c mmu c t fr ely th ch th thr ugh the u re pu pillary ape rt . ri o r ch a mb er o i n o o i su r Th e a n t e , b unded fr nt by the c ncave nner th i e of th a o f th e o ea is i i e e i e a o e i i . f c e c rn , l m t d b h nd by nter r surfac r s

a e ra e e two w l s e in th e e io i nterna l sclero- corn ea l L t lly, th s a l m et r g n Of the r w a i as i ri ial or ltra tion a n l u n ction w e re o s o e. j , h they f m h t kn wn the d fi g n ra th e o s io wa of th e an rio a e o es o to a Ce t lly, p ter r ll te r ch mb r c rr p nds th t po rtion of th e an terior surface of th e lens which is exposed through the th e u en h of a io a e i . e . o i . T e pup l depth the nter r ch mb r, meas rem t fr m the poste rior s urface of th e central p art of th e cornea to the anterio r s a of e o e ou i i in e urf ce the lens, xp s d thr gh the pup l, var es the sam

1 6 ANTERO - POSTERIO R SECTI ON S O F TH E EYE

' e e wee t h e i ris an d i n er a ero - ornea ti n ction Cl ft b t n the t n l scl c l j . H e re f im o r a s ru res an a en io n a numbe r o p t nt t ctu dem d tt t . f i e io are i a e in 0 2 G oo i s o 5 . 1 8 an d 1 0 d v ew th s r g n d spl y d N , , 3, 4 , 5 , but it will be n oticed th at the app earan c e in all of th es e ph o tograph s b e d oes n o t c o rresp o nd . It will Observe d th at th es e differen c es b ear e re a io to a e o f o n ra io of iris f r in No o o . ere s m l t n the st t c t ct n the , I , wh th e e i n e i i a a u i wi a i an d s re e iri th e sp c me xh b ts sm ll p p l th th n t tch d s , form of the iridial angle is n ot th e sam e as th at sh own i n t h e ph oto s 8 and 1 0 i n i th e i s are o r i i a a No . gr phs 3 , 4 , 5 , , wh ch pup l m e w dely d l ted , i t o its ra ia o a io and the iris thicke ned ow ng d l c ntr ct n . a i i e i a u i o f in r e ia e i a T k ng a spec m n w th p p l te m d t s ze , such as th t

i it i be er a at t h e i n a r - en n . e o o ea se NO 4 , w ll Obs ved th t nt r l scle c rn l ju n ction the c o rn e a is thick e r th an th e s cl e ra ; in order th at the two e dge s may be bro ught into h armo ny th e p ostero - in te rn al m argin of th e o ea is o u n e off s o as t o o r a o e in s o e r i o e c rn r d d f m pr j ct g h uld , wh ch v r h angs th e slopin g su rfac e of the scle ra with which it unite s : this is well s een on th e l e ft side of th e ph otograph . Th e res ult of this arrange ment is th at a rec e ss or groove is form ed imm ediate ly behin d the s clerO - c orn eal ju n ction which c o rrespon ds with th e extre m e p eriph e ry r of the anterior Ch amb er. When describing th e manne in which th e i i o r e o f th e i i was a a e t o t h e i iar o a e io n C l ary b d r r s tt ch d C l y b dy, tt nt was drawn t o th e fact th at th e attach ed edge o f the iris was tu rn e d b en in Nos . o e n 8 an ome w a a wa as ma e . d s h t b ck rds C nsequ tly, y se 4 , 1 0 w e ro o a io of its a ia es th e iris i s i en e its , h n th ugh c ntr ct n r d l fibr th ck d o e i e or s e e e in o of its a a e ut r c rcumf rence f m a b vell d dge , fr nt tt ch d i i i o th e o o in th e o a of an marg n , wh ch fits nt gr ve uter w ll the gle i ia i th e i e a e o - or a io th e o e a mmed tely beh nd nt rn l scl r c ne l junct n , f r p rt of oo o es o i t o o an in o er o f o n ea the gr ve c rr p nd ng the verh g g sh uld the c r , th e o uter wall b eing form e d by th e slope of th e s cl era imm e diately

- behind the intern al sclero c orn eal junctio n . In this way a re cess is ro i e ei i e ar i of th e iri can be i raw p v ded wh r n the th cken d m g n s w thd n , i o o e e i a in th e o i e a io o f th e a e e ee w th ut , h wev r, n cess t t g bl t r t n sp c b tw n in h i er e i re the oppos g surfac e s . The d eepe st part o f t e nt v n ng cess is n e i o thus left ope for the fre e circulatio n of fluid s . A bett r v ew f this oo e i for o e ie n e ma be a e the sulcus circula r is gr v , wh ch c nv n c y c ll d cor neae can ai e arin th e i i a a ro its i ia a a , be Obt n d by te g r s w y f m C l ry tt ch

en i is s o in o . 1 2 e roo e is is a e a m t ; th s h wn N , wher the g v d pl y d as d ou ble co ntour lying in fro nt o f th e linear area fro m which th e iris has u are e been d etach ed . F rther dissectio n s of th e s am e features repr sente d o 1 2 nd n d in No 1 h e s e on a e n N s . a a i i . t e oo 47 , 4 gr v further d m str t d by the e xpedien t of pulling back the iris after the l en s has b ee n re o th e o o of the e th e i i ia a a n m ved . But b tt m r ce s s between r d l tt chme t an d the inner su rfac e of th e sclera is n ot s o cl ean - c ut as might be u i n iris on th e in o . o o o o f is o e supp sed C rv ng r u d the b tt m th , fr m the n r

F I G . 1 . E NL A R G E D G ENER AL "IEW OF TH E IRI I N L E D AL A G .

a . Cana of S h e m l c l m .

b. Tra e cu ar t ss u e o f ect n ate am b l i p i lig en t .

c. S c le ra n l ve i . ' D a . e n s e s e r cl al t is sue . e . S c le ral pro c e s s o r s p u r p roje ctin g i n war d s an d fo rward s fr m h l o t e s c e ra c lo s e be h in d t h e can al of S c hle mm ; t s o rre s o n s t o t h e a n n u ar l am e n i n hi c p d l ig t s e ctio n .

. a m u f R dial s cu lar fi b re s o f t h e i ri s e xt e ndi n g o utward s e ow t h e r ia an b l i id l gle .

. Ir n g idial a gle .

h . e r o n al fi re s o f t h e C ar m u e M idi b ili y s cl .

i . C rcu ar fi res of t h e C ar m u s c e i l b ili y l . Th e m c r h o to i o p graph h as b een s ligh tly t o u ch e d u p s o as t o e mph as i ze t h e ffe re n t at o n o f t s s u e wh c h is re ea e t h e a o r di i i i i v l d by M l y stain . ANTERO - POS TERlO R SECTION S O F TH E EY E 1 7 side to th e s lo ping s urfac e of th e s cle ra j u s t be hin d th e inter nal s cl e ro corn eal ' u n ction is a a o of lax e u ar i u e th e s a e j , a sm ll m unt trab c l t ss , urf c of i i to rior is o ai an o e i wh ch , d rected the ante chamber, verl n by end th l al c ove ring c ontinu o us in fro nt with the end oth elial laye r lining the ’ inner s u rface Of the poster ior limiti ng membrane of the c ornea (D es cemet s membrane an d o ue i wi io en dot lia a er ) , c nfl nt beh nd th the anter r he U y f i l i n a o i . i o wi ax a e e the r s Th s , t gether th the tr b cular t ssu be e th ’ o i in u o f s m a is f rmed by the spl tt g p Descemet me br ne , the feeble representative in man of . the much m ore extensively developed in m a s o a th e i th e ectina te structure seen ma m l ther th n Pr mates , called p i a m t a i i i o f i i e a i e on l g en . The l x ty and elast c ty th s t ssu can e s ly be d m strated in i e in on th e i i e i a recent spec men by g ntly pull g r s , und r wh ch o i io oo as t o be o i a s o i a i c nd t ns the gr ve, such , tends bl ter ted , s mul t ng th e a e i e in o o a s Nos . 2 the ppearanc d splay d ph t gr ph I and , where iridial angle n ow exhibits an app earance m o re clo sely re se mblin g th e es of it es e n i e o e e i en s figur pr nted i the var o us t xtb o ks . In thes sp c m 1 n an d (Nos . an d 2) the pupil is co ntracted and th e iris is thin ed much s tretched ; unde r th e se c o nditio n s the tractio n exercis ed through its attached margi n pulls ou t th e lax tissu e which forms th e floor and o e of th e iri ia a e an d so a to th e o or e s ut r wall d l ngl , le ds m re l s c omplete o bliteratio n of the groove s o well displayed in th e oth er o o r N 8 e e i e a i a io o f is a os . o ph t g phs ( 3, 4, and A m r d ta led x m n t n th regio n und er a high e r d egre e of magnificatio n will en able the stud e nt t o realize the ge n e ral arrangem en t o f th e parts arou nd th e iridial angle : Fi 1 i s a o o i i i i a e . g . ph t m crograph c v ew of the appearanc e s d spl y d Th e uppe r edge of the figure passes thro ugh th e c ornea an d s clera at th e e e of th e i er a s ro - o io i r idia l or l v l nt n l cle c rneal junct n . The filtra tion angle (g ) lie s b etween the per iphery or cilia ry atta chmen t of the i r is i ern a an d sclera r re s e a nt lly the with its asso ciated st uctu xtern lly . ’ Th e e a i s e a a e s e as ma be s in th e s e io dens scler l t s u ( ) tr v r d , y een ct n , by a e a in c ie s to o er si e f n e o a — ca n a l scl r l ve ( ) , l the ut d o a l ngated cleft ( ) the o S chlemm — o wa of w i it o rio t o th e a f the uter ll h ch forms . P ste r can l o f Schl emm a wedge - sh aped pro c e s s o f scleral tiss ue (e) is s ee n pro ectin i and o h u a j g nwards f rwards from th e s ub stanc e o f t e o te r co t . This repre sents th e appearance displayed by th e an n ular lig a ment on se io an d h as a e sc ra r alca r s clera ct n , been n m d the le l process o r spu (c e) . Lyin g In fron t of this an d t o th e inner sid e o f th e can al of Schle mm (a) is the trab e cular tis sue of the pectinate lig a men t th is c on sists of an o e e o of fibro - a i i e on in o i n ron i p n m shw rk el st c t ssu , c t u us f t w th ’ s n e i i h f th e orn es t e n n r s u r e o ea . Descemet membra , wh ch l n i e fac c o e ior o i of of th e i a e a e are P st r ly, the maj r ty the fibres pect n t lig m nt

1 F o ‘ r a fu ller accou n t o f t his r egi o n s e e a pap er On t h e G ro ss An atomy of t h e ’ F trat o n n e o f t h e H uman E S e . T o m s on The O hthalmos co e e tem e r il i A gl y , A h , p p , p b , 1 1 0 an d u 1 1 1 9 , " . ly, 9 1 8 ANTERO - POSTERIOR S ECTI ON S OF TH E EYE s ee n to be attached to th e fro nt o f th e s cle ral proc ess (e) ; a fe w o f e o e a wa o th e s m i o f th e o es th m , h wev r, pass b ck rds ver u m t scleral pr c s an d blend with the co nnective tissue which s u rro u n d s th e b otto m of i i ia an e o in o i o in e a i s o the r d l gl (g) , bec m g c nt nu us t rn lly w th the tr ma f iri e i th e s era ro s s e an d o e a ie t o th e s . B h nd cl l p ce ( ) cl s ly ppl d o the i e a of a d are th e mer i diona l bres of cilia r nn r surf ce the scler ( ) , fi the y m uscle h e it o e do n ot in o or o i ( ) ; th se , be n t d , pass fr nt ver the summ t o f th e s cleral pro ce ss (e) . To the inner s ide of the meridio nal fibre s lie th e circu la r bres of ciliar m uscle and t o of e as fi the y the mass thes , ow in e io ma a of i e o f sh n s ct n , y be traced few the scattered rad al fibr s dilator a il ae the p p l (f) . ca na l o S chlemm d is e e an e o e ia The f ( ) r veal d as empty, Op n , end th l l in e a in its o e wa o r e s a s d i l ed cl ft , h v g ut r ll f m d by dense cler l ti sue ( ) , wh lst it s inner wall is made u p of th e trab e cular tissue o f th e pectinate liga h As h e a na ie n h ment ( ) . t c l l s i this p ositio n its hinder part o ccupies t e an gular re cess formed by the inward and forward projection of the

o e . ar is s o f th e e i e i as scleral p r cess ( ) The trabecul t ue p ct nat l gament , ’ it i to i s i o f s n a is a a o l es the nner de Schlemm ca l , tr versed by m ny narr w a i are i e an e io of e o ia ch nnels , wh ch l n d by xtens n the nd thel l layer ’ i o e ies e s e a e an d af o - for wh ch v rl D cemet s m mbr n , f rd a passage way i ro e io e i n o th e a a of e Th e flu ds f m the ant r r chamb r t c n l Schl mm . can al of Schlemm is th erefore a chann el or se ries of ch annels p ossessing o or es i i wa to i of th e i m re l s r g d external lls , due the dens ty scleral t ssue i i n s s it w i its i n w o it is o wh ch here ve t ; h lst n er all , f rmed as by the pen u a i s o f th e i i a i be s u e t o trabec l r t s ue pect nate l g ment , w ll bj ct such e ma be in du th f a i chang s as y ced by e stretching o th t t ssue . 1 h as a th e ra ro e is n ot a e oin It been suggested th t scle l p cess ( ) fix d p t , but respo nds to the influence of the c o mbined co ntraction o f the ciliary e an d i of th e i o i war an d i a muscl the sph ncter pup l , m v ng back ds nw rds , thereby stretching th e pe ctinate ligam e nt an d op e n ing u p the iridial at a e i a it u inwa s th e i n al of th e a a angle , the s m t me th t p lls rd n er w l c n l of e s o i r i its u e an d e es is i a on i io Schl mm , nc eas ng l m n th reby tabl h ng c d t n i r w in i e u s a t o o of negat ve p essure ith t . Wh n the m scle ce se c ntract the scleral pro cess is pulled forward again by the elasticity of th e i i a e n o f a a is e and a e s pect nate l g ment, the lum the c n l reduc d , gentl pre su re is exercis ed ou its c o ntents s o as to forc e th e m o nwards into the F or th e e i e o n w i i io is surrounding circulation . v denc h ch th s suggest n i i based see the art cle already c ted .

Th e R eti n a or o i . a in e , nerv us tun c The re der may be rem d d that th is layer is formed by th e invaginatio n of th e wall of the prima ry optic e i two wa s of i th e cu is v s cle to form the optic cup . The ll wh ch p or are ori i a e a a i o f o i e i f med g n lly s p rated by the c v ty the pt c v s cle ,

‘ n Th o ms o O h a lmosco e ol 1 1 1 Th F rat o n e . n th v . u e t p p , ix , "ly, 9 , il i A gl , A , 0 p . 47 . ANTE RO - POSTERIO R S ECTION S OF TH E EY E 1 9 a s pac e which at an e arly stage o f d evel opm e nt is c on tin u o u s with th e

i - f e n ri a i of t h e rai . o e i c u o v t cular c v ty b n Th s d uble wall d Opt c p , which the inturned edge c orresponds in the adult t o the circumferenc e of u i o t o a o a o it a r or the p p l, c mes h ve devel ped r und the uve l t act

' o er of th e o i cu is o o vascu lar c o at . The ut wall pt c p theref re cl sely

i e to th e i - a e of th e a r i to appl e d everywher nner surf c uve l t actr v z. the orioi th e o r i i i i th e i i o s i i To ch d , b culus c l ar s , c l ary pr cesse , and the r s . th e inn e r side of th e o uter wall of th e optic cup lies the inner wall of cu r at s e ai o f i of o i the p , sepa ated fir t by the r m ns the cav ty the pt c vesicle— a sp ac e which i n the adult is rep resented by the inte rvals betwe en th e rods an d c o n es and the pro cesses e xte ndin g fro m th e e o o r o for i i pigment c ells . Ther seems g d eas n bel ev ng th at th ese in a o i a e th e two a Now th e terv ls c nst tute lymph space b tween l yers . two walls of the cu p unde rgo rem arkable changes in the pro ce ss of o o e of o e a o e r devel pment . The wh l the ut r w ll bec m s c onve t e d into in i a i men t la er o f r i i as h as a th p gmented l yer, the p g y the et na . Th s , e a is ie t o i s u o f an d s o be n st ted , appl d the nner rface the uveal tract , intim ate is th e unio n that in dis s ecting the c oats of the eye it generally to i a ou n i for i i as adheres the vascular tun c , thus cc t ng the v ew wh ch w formerly h eld th at it was t o be regarded as o n e o f th e c o nstitu e nts of the uveal or ch orioid layer . Its separation from th e inn er wall Of th e optic cu p takes place alo ng th e lin e of the cavity of th e primitive optic esi e w e e th e io o f th e two e a ear to a t a v cl , h r un n lay rs pp s be we ker h n the co nnexio n between the pigment layer o f the retina an d the inn er f h surface o t e uveal tract . i e a of o i cu w i is r w i to th e The nn r w ll the pt c p , h ch eve y here appl ed i s u of o e or i e a oes in th e nner rface the ut r wall p gment d l yer, underg pro ce s s of development ch an ge s which vary in acco rdanc e with o i io i it o i o i e as far or the p s t n wh ch ccup es . Fr m the opt c nerv f wards as ora ser ra ta i of cu o nervous la er o r the , the nner wall the p f rms the y ti a reti ae n i i r i ars o c n . o i r p p In c trast w th th s elat vely th ck st atum , the i n n er wall of th e optic cup in fro nt o f th e o ra s errata bec o mes reduced to i e of a in a e i n ow o e the th ckn ss s gle cellular l y r, wh ch , m r firmly e t o i o e i in a of a struc adh rent the p gment layer, v rl es the ner surf ce th t e an d is o i e o a s o orbiculus cilia r is th e cilia r tur , c nt nu d nw rd ver the , y rocesses nd th e o rio s u a of th e ir is i th e tw a iz a o v . p , p ste r rf ce unt l l yers, o e o o i r an d ou er a s o f th e i cu e o e th se dev l ped fr m the nne t w ll Opt c p , b c m i u o o h e i re of th e u i a a e c ont n us with each ther at t c rcumfe nce p p ll ry p rture . o i i o ro m i n r wa of i Acc rd ng as th s stratum , devel ped f the ne ll the Opt c cu o i s o i u an d i iar ro ss es it is s o e n o f as t h e p , verl e the rb c lus c l y p ce , p k a rs ciliari s retinae i e it is a ie to th e o e ior su o f p , wh lst wh re ppl d p st r rface i i r s th a rs i r d a r etina e the r s it is refer ed t o a e p i ic . A c o nsideratio n o f th e foregoing details will enable th e s tu de nt to ea i e om e i of th e a er i is now ei o i er an d r l z the c pl x ty l y wh ch b ng c ns d ed , "2 20 ANTERO - POSTERIOR SECTI ON S OF T H E EYE

will acc o unt fo r th e apparent discre pancie s which th e dis s ectio n s reveal r i a on e o i a e Th e wh en we attemp t to examin e the et n as rgan c l y r . facility with which th e pars optica retina e separates from the external or pigmented laye r is o ne of the difficulties which the pr epa ratea r has o an to o to o o e in th e i of io c nst tly endeav ur verc m mak ng large sect ns , and it is o in io a a to i of nly except n l cases , due p rtly the effic ency the

a i a o to oi a of o - o h rden ng re gent, and als the av d nce p st m rtem change , a i th t satisfactory results can be o bta ned . i t o w i a an d i Ow ng the changes h ch take pl ce after death , the nfluence of th e ar i o a rs o tica r etina e o e its h den ng reagents empl yed , the p p l s s n o rm al transparency and acquire s a mat - white semi- translucent appear er in of i a o a of th e ance furth , place be ng evenly spre d ver the surf ce o ioi it to o ea an d w i in ri io a direc ch r d , tends bec me cr sed r nkled a me d n l 2 8 10 i in N s . 1 . o . a are e o t n These ppearances well s en , , 3, 4 , and In some o f the specimen s m ore or le ss extensive separation has tak e n place between th e intern al nervo us layer and th e pigmented lamin a o f i i i i it i r Nos . 1 and 2 o o a w the et na . are the ph t gr phs h ch exh b t w th least i u f r a a io a e o . o o o d st rb nc the pa ts In the ther ph t gr phs , where sep rat n o e two a e it i o i th e has ccurred b tween the l y rs , w ll be n t ced that by intu rning of th e cut edge th e o uter surface of th e nervo us layer is often os an d is it i o is o i i exp ed , th , w ll be bserved , free fr m p gment , the p g mented layer to which it was applied being retained in s itu in c ontact i i n r w th the n er su face of the ch orioid . Pro c e eding n ow t o examine the pa rs optica r etinae as displayed in i io s e io of e e it i be t o o in i i mer d nal ct ns the y , w ll seen f rm the ner l n ng of w of th e as far o ora serrata i as the all eyeball f rwards as the , wh ch

i i 6 - in external a s o 6 2 see o . 10 rule s tuated ab ut mm . ( , als p ) beh d the sclera- cor nea l io junct n . Acc ording to wh ether the meridional section h as been m ade in th e o i o a or i a iffe is to o e in th e e i h r z nt l vert cal plane , d rence be n t d r lat ve o i io of th e a a of o i o o p s t n p ss ge the pt c nerve thr ugh the scleral c at . a Nos 1 and 2 e i i i a ar e e th e io n is Ph otogr phs . xh b t th s ppe anc wh n sect carrie d h orizo ntally through the optic n e rve h ere the nerve is seen to r s e o i t o n or i of os io o of pie ce the cl r t c 3 mm . o e other s de the p ter r p le the o of i a ra e th e o n e i e of a rs eye . In c nsequence th s r ng ment , s d the p tica retinae as e in n s o e o io is or e a o . p , se n sect n , sh t r th the ther The h rt r si e is a i o o to a of o d lways that wh ch c rresp nds the nas l surface the gl be , whilst the longe r side lines the in ner su rfac e o f the temporal aspect o f a th e in a i an e the eyeb ll . When meridion al s e ctio n is m ade vert cal pl i ro o i oi of e of th e pass ng th ugh the pt c nerve , the p nt entranc nerve o o o o to the o io o e i i a o c rresp nds m re Cl sely p ster r p l , be ng s tu ted nly o 1 o it o r n i iff ab ut mm . bel w ; c nsequently the e is o ly a sl ght d erence in th e extent of surface covered by the upper and l owe r parts of th e i i i i 6 and . s a e in os . N . ret na Th s well d spl y d 3, 4, 5 , 9

2 2 ANTE RO - POSTERIO R SECTION S OF TH E EYE

s of th e i a s o as to ea e er o th e o e and e i layer ret n , l v h e nly c n s th r a a e and o i io o f associat e d c ells . The ppear nc p s t n th es e parts will be e e er oo w e th e u of th e o is a i e b tt r und st d h n fund s gl be ex m n d (see p . a e io s eir o i io ma o b but in m eridio n l s ct n th p s t n y als e made o ut . o r a e a th e i a in is e io er o Unf tun t ly, fter death ret n th r g n und g es usually a m a io of its a s so a o i ion of th e a a is tu ef ct n l yer , th t the p s t m cul gene rally recognized by th e prese nc e o f a pron o unc e d fold exte nding o o a illa o tica for e of r in . o so a utwards fr m the p p p the spac 5 mm , h v g at a oi or a i e o e o th e f h e a o . o t o i i p nt b ut 3 mm , l ttl v r, fr m centre pt c d sk or a i i i i or io a n p p lla a d st nct d mple depress n . The l tter i dicates very i of th e a ce tr lis To precisely the p osit o n fove n a . this fo ld th e n am e lica cen tralis was i it was o e e ri e as a p appl ed , and f rm rly d sc b d a n o rm l o i ion o f th e i a n ow o it is o i as a o c nd t ret n ; , h wever, rec gn zed p st o e i e n o o th e o e a o io o f m rtem chang , nduc d d ubt by m r ready bs rpt n Th fluids by this p art of the retina . e two c o nditio ns are very clearly n o a N 8 and in th o in o s os . e of w i th e sh w the ph t gr ph , 5 59 ; first h ch o o a e i n o i io we in es a e fundus was ph t gr ph d the fresh c nd t n , t nty m ut ft r i i e i in No th e a e o . s i en was o o r m val dur ng l f , wh lst 59 s me pec m ph t graph e d after subjectio n t o the i n fluenc e o f a 4 % h ardening s olu r o o is n ot er r tio n of fo malin . Th ugh the f ld h e p ese n t in its m os t i o i a e n o i in e o i i th e typ cal f rm , the reader w ll h v d fficulty r c gn z ng altered appearance due t o the swolle n and oedemato us c ondition of th e parts . In th e meridio nal sections th e dispositio n of th e fold will vary

o i to in i s ion is a e . s if the acc rd ng the plane wh ch the ect m d Thu , h e io a o i on o n e see No . th e o wi ro t e s ct n be h r z tal ( I ) , f ld ll stretch f m o r si e o f o i o a th e os e io o e oi i e i ute d the pt c nerve t w rds p t r r p l , c nc d nt w th w i or ar s o ovea centralis is w i if th e e ion h ch , ne ly , the f placed ; h lst , s ct i a o i be s e t o at ri a e t o a o f be vert c l , the f ld w ll en pass ght ngl s the pl ne e io owa e o a or o i of s as is the s ct n t rds the t mp r l uter s de the fundu , n N nd 6— an a e i e a e u s to dis o i os . a sh wn 3, 4 , rrang ment wh ch n bl s ting uish th e lateral or te mporal fro m th e mesial o r n asal h alf o f any e i o o r a we are n ot i o e eye xam ned , th ugh unf tun tely able , w th ut furth r

a a to sa e i w e th e e e e on s to ri or e i e . d t , y d fin tely h ther y b l g the ght l ft s d Fro m the optic e ntranc e t o th e o ra serrata and in fro nt as far as th e i i o e e i a is a out o a ai s the i e c l ary pr c sses , the r t n spre d and f rced g n t m ddl oa e e i e vitreous humour e ern a c t by the pressure x rc s d by the , the xt l — — investing membran e o f which th e hyaloid membra n e is e verywh ere is n ot e in c o ntact with th e inn e r surface o f th e retin al layers . It asy in all the sectio ns t o make o ut the e xist e nce o f this hyalo id m embran e n i n a e r in N 1 0 i a o o iew of it is as a e o . nd pende t l y , but qu te g d v o in e e e to i i e o f th e e a of o i e e it bta d , wh r the r ght s d ntr nce the pt c n rv h as in p art be co m e se parate d from t h e in n e r s urfac e of th e underlying a re tin . ANTERO - POSTERIOR SECTION S OF TH E EYE 23

ora s errata as h as e n a e a s e ni e th e The , b e st t d , m rk very d fi t ly a ior i i e in — th e rs o tic r ti ae In o of nter l m t of the visu al r t a pa p a e n . fr nt i or th e re i a n o o o o of o s e is con th s b der t n , l nger c mp sed nerv u elem nts , tinu ed o as th e i a a th e a rs cilia r is reti nae w i f rwards th n cellul r l yer, p , h ch in co njunction with the pigme nt layer ove rlies th e inner su rface of th e i i o c l ary b dy . i th e As th e ora e a a l s Si a e 6 . a o a rule , s rr t tu t d mm beh nd extern l scler o n io is a a a ie o f o ma e in c rneal ju ct n . It d pl ys v r ty f rm , as y be se n the iff N 1 to 1 0 in all r is e i e n e a i e e ot o r os . d r nt ph g aphs , , but the e v d c th t th s e dge of th e nervo us retina is here m ore firmly co n n e cte d with th e sub a a for as i io of i j cent l yers , , may be seen by an nspect n the spec mens , alth ough the pars optica retinae tends to separate readily from th e i i i i a i i a io e underly ng p gment layer beh nd th s m rg n , th s sep rat n n ver s in o of it i o i io is i take place fr nt . Th s c nd t n further emphas zed by the a a i o i e i a o i it ma f ct th t just at th s edge the pars pt ca r t n e , w ng , y be , to the action of p ost - m ortem change s or th e influence of the hardening a to o a o o o i a i ma re gent , tends f rm sw llen f ld al ng th s m rg n , as y be we in N 2 1 0 n 1 o No os . a d o s . ll seen , 4 . In ther examples , h wever ( 7 , 8 ou i i ar i is not i . and th gh s m l ly treated , th s appearance d splayed Careful m easurem e n t reveals th e fact th at th e ora serrata reaches o wa o n n an on o i e o f o further f r rds the asal th the temp ral s d the gl be . Thus th e average distan ce of th e o ra serrata fro m the c orona ciliaris on ia i of e e is i on a of the med l s de the y mm . , wh lst the lateral spect the

o e th e ea i a e e e e e two s ru e is - 2 gl b m n d st nc b twe n th s t ctur s 4 mm . In some of the specimens the ora serrata displays a scall op e d edge i i a e ie of oi 05 . and th e i s e e (N 5, 7 Here marg n nt rrupted by s r s p nt d processes separated by backwardly directed c o ncave n otches . From the pointed pro cesses there occasio n ally extend forwards on t o the o i i i i for ia i i in i es rb culus c l ar s a var ble length th n wh te l es ; these l n , w e are a i owa th e e or i a hen pres nt, usu lly d rected t rds vall ys nterv ls th e i i o o r it to a i i o between c l ary pr cesses , may be sm ller c l ary f lds i lie th e r e i o i wh ch between large o n s . Oftent mes a m re deeply p g mented a th e i - i a i o a str nd replaces wh te thread l ke bundle , p ss ng f rw rds o f r in o i fr m the p oints o f the serrated edge o the o a. If an rb culus which h as be en dissecte d off fro m the scleral coat these be viewe d by s o r i e i ar a ia i e to o tr ng t ansm tt d l ght , the d ker r d l strands w ll be se n c rre s ond to ea e of fi n e e s o e i a o ne in i e p l sh s v ssel , ft n w th a l rger the r centr , passing back fro m th e ciliary pro cesses or th e intervals between them . It is als o n oteworthy th at th e spiny appearance imparte d to the edge o f the ora s errata by th e pres e nce of these p ointed processes is always e o n a a i e e o i is n a ow on b tter seen the n s l s d , wher the rb culus rr er, than th e o a i w e e th e ora a a s ua i a a o e e n temp r l s de , h r serr t u lly d spl ys m r ev r it is not o o to e i en e of th e appea ance . Indeed , at all unc mm n find v d c n n th f h o ra pointed pro cesse s o ly alo ng th e asal s ide of e e dge o t e . 24 ANTE RO - POSTERIOR SECTION S OF TH E EYE

o o o to o are e in o a s and e e to M re c mm nly, , they best s en y ung dult , s m e to i a a in th e e of o th e o ra s e a a e re t nd d s ppe r yes lder subjects , rr t th n p i a mor e e a a as is i a e in N 2 8 n . os . a d sent ng e v n appe r nce such d spl y d , 9 is of a o i Th e o o . o a i e in o ph t graph , NO 9, that a p th l g c l spec m n , tr duced in o ie fo r o o it e i i a a a t the ser s an ther purp se , but xh b ts rem rk bly even i e o i e on a ora s errata and s her n t c d th t account . Th e numb e r of these p oin ted proce sses is extremely variable ; in

r a e e - o o in N o e e a e e as os . 1 in o s m th y l rg and w ll pr n unc d , 7 and 4 ; thers ar a and or e a in e e o s o . 1 0 . as th y sm ller m e num r us , N As many 34 a e n o in o a o 1 or 18 e e o i e h v bee c unted ; ther c ses nly 7 hav be n n t c d , whilst in s o me in stances it h as been impo s sible to recognize th eir presence at all. What strike s on e fi rst on examining th e pa rs optica retinae in the foetal 1 16 1 8 is th e e e Nos . 1 a e n a of i a e . y ( 5, , 7 and ) app rent r du d ncy th s l y r e i o i io is o a ea it is i to s a Wheth r th s c nd t n m re apparent th n r l d fficult y, as poss ibly the relatively thicke r an d s o fte r Character of the tissue may render it m ore s usc eptible to post - m o rtem changes ; but in m os t of th e spe cimens examin e d th e appearanc e s ugge sts th at the re tinal laye rs are n ot yet ade qu ately stretch e d over the inner surface of th e vascular an d o e i e o s of e e i o e to i i a a th e pr t ct v c at the y , wh ch w uld s em nd c te th t e xpansio n o f the retina over the inner surfac e o f th e glob e was n o t o ff its own in in i o e c mpletely e ected by tr s c gr wth , but rath r by a stretching and spreading ou t of its laye rs o n th e inner surfac e of th e n a i ioi n o is to is growi g nd expand ng ch or d a d sclera . Supp rt given th i w o o o i a i io of e of o i v e by the phthalm sc p c ex m nat n the yes y ung ch ldren , ‘ in wh om th e watered silk appearance displayed by th e retina is accounted for on the supp ositio n that that membran e is n ot yet evenly h n n o e t e is o i o o . stretched v r fundus , but thr w t f lds As e i in i i i o of th e i a has be n sa d , br efly descr b ng the devel pment ret n th e of th e or a a i of th e o i cu (p . at level a serr t the nner lamella pt c p o e dis undergo es a rapid tran sitio n in structure . The nerv us el ments a e and all a i to e s i wa is i i a com pp ar, th t rema ns r pre ent th s ll a th n lam n p os ed of a single laye r of c olumn ar c ells which n ow beco mes intimate ly o i e i o i it can c nnected w th the externally plac d p gment layer, fr m wh ch , wi o i i u be a a . are not e o e nly w th d ffic lty, sep r ted We her c ncern d th a co nside ratio n of the qu estio n what elem e nt in the retina is represented i r is reti nae is by this layer o f c ells wh ich con stitute s the pa rs cil a . It sufficient for our purpo se to n ote that as we trace this layer fo rwards it n e oe a a i n i i o i e io in en of u d rg s gr dual th n ng, nv lv ng a r duct n the l gth the o e so a e a in i i e i i i of th e ora c lumnar c lls , th t , wh re s the mmed at v c n ty s e rrata these cells are of consid erable height (the figure s give n are from

0 0 0 to o ° o o mm we on e a i i e o ie i ia 4 5 ) , find x m n ng th m as they verl the c l ry ro o m u r 0 0 1 Th e i e s fa e of is p ce s s es th at th ey nly eas e 5 mm . nn r ur c th a h as i as o i membrana l yer been descr bed f rm ng a glassy membrane , the ANTE RO - POSTERI O R SECTIONS OF TH E EYE 25 limitans cilia r is e a a e o f is a is n ot n . The x ct n tur th l yer well u der s oo its i s o th e r e s a oi is a o th e a t d , but ntere t fr m p es nt t ndp nt b sed up n f ct th at it affo rds a means o f attachment to th e fibre s and lamellae which s o th e i i o o th e n s o i th e zonule o tretch fr m c l ary b dy t wards le , f rm ng f inn Z .

“ The pa rs i ridica reti nae is m e re ly the fo rward extension of the p ars ciliaris retin ae lining the inner surface o f the pigment layer which clothes th e poste rior surface of the iris at th e pupillary e dge of th e iris th e s e two l aye rs bec o m e s tructurally c on tinu ous with each oth e r by a o e e i in th e a es rim of s e o a f lded dg , wh ch , dult , repr ents the the c nd ry o i r cu Th e of th e a e r o i th e i pt c vesicle o p . cells l y f rm ng pars ridica e i a o r lo o a e a e i i of r t nae h ve, h weve , st the c lumn r arrangem nt ch ract r st c th e ars i i ae an d n ow i i a or i a A i i e o . s e p c l ar s r t n , exh b t m e cub c l f rm th y pas s o n to the po sterio r surface of th e iris th ey beco me loade d with i so a it is i o s i e to i i i o i p gment , th t mp s bl d st ngu sh them fr m the p gment a f i o i e l yer prop e r o th e re t na up n wh ch they r st .

Th e p igm en t la yer of th e retin a . Sufficie nt reaso n s have b ee n already advanced for regarding this laye r as m orph ol ogically a part o f th e i a i as has o it is e e o o th e o e ret n , s nce , been sh wn , d v l ped fr m ut r wall N r of th e e cto dermic optic cup . o ne e d much spac e be devote d to its i io for in es ri i o th e o s e in a an d th e descr pt n , d c b ng b th nerv u r t ch orioid it has been repeate dly re fe rred to as o ccupying a positio n tw s interm ediate b e twe e n th es e o structure . It s t o a e to th e o ioi o e a e to tendency dher ch r d has als b en llud d , a tendency which involve s it s separatio n fro m the laye r to which it more iz th e a o i a e i a Th e o a i i f th e o er o v . . o pr p ly bel ngs , p rs pt c r t n pr b b l ty exis te nc e o f a lymph space betwee n th e s e two lamella h as als o been e to an d it en oi ou t a in o e e e referr d , has be p nted th t the fully devel p d y this cl e ft repre s ents th e cavity of the prim ary optic vesicl e . Th e pigm e nte d layer of the retin a lin es the wh o le of the inte rio r o f th e uveal tract from th e entrance of th e optic nerve to the pupillary margin of the iris ; internally it is overlain by the pa rs optica retinae as far o a ora serrata in ro of w i in a e e and f rw rds as the , f nt h ch , the h rd n d e e its o o is o th e i a rs cilia r is retinae fixed y , c l ur revealed thr ugh th n p , whilst wh ere it passes ove r th e back of th e iris its intensity o f c ol o ur is rein o th e i wi in th e of th e a rs ir idica retinae f rced by p gment th cells p , i h th e o io w i is in o a it . as ee sai o e h ch c nt ct w th As b n d , alth ugh c nn x n betwe en this pigm e nted laye r of the retina and th e p ars optica is fee bl e and a i u e its io i i i i and i i i is e s ly rupt r d , un n w th the pars c l ar s r d ca much F or er e ai on e in m ore co mplete an d difficult to separate . furth d t ls c c rn g

6 . e i a se e . the r t n pp 44, 5 l n s In eri io a e ion of th e e e a the e s e s The e . m d n l s ct s y b ll l n app ar s u spen de d within th e cavity of th e glo b e in s u ch a po sitio n as to s ee m to plug posteri orly the pupillary aperture ; it is thus brought into 26 ANTERO - POSTE RIOR SECTION S OF TH E EYE re io i i i i o e it e ia i n ont its i lat n w th the r s, wh ch t uch s tang nt lly fr ; c rcum fe rence is dire cted towards the blunt projecting e nds of th e ciliary o e o i o e it is a i e a pr c sses , fr m wh ch , h w ver, separ ted by the c rcuml nt l

a e wi of w i as a e a a e s a o 1 . sp c , the dth h ch rul ver g b ut mm It is h e re th at by c areful in spe ctio n an d th e u s e of su itable light one may o bs e rve the arrange me nt by which the lens is su spended an d e n i o i of i i o i th e s i o io . o us nsor h ld p s t n A g d v ew th s, wh ch c nst tutes pe y in N 8 li a ment of th e o r zon ule o inn is o . o in No . . g lens f Z , seen and als 9 Th e a er i is rom a a o o i a a a io in i i l tt , wh ch f p th l g c l prep r t n wh ch the ent re iri is e to o io a of o is i i e s adher nt the p ster r surf ce the c rnea , ncluded , s nc th e iris being pulled fo rward permits the bette r illuminatio n of th e i i in i e i n ot i in s a ow i i a e n a s i . l g m t , wh ch th s c s ly ng h d beh nd the r s n N 2 i os . an d a e a a e are ain s e . i th e The s m appe r nc s f tly en 4 Beh nd , s on th e a e io a o f th e i r o o r in a o lens rest nt r r surf ce v t e us hum u , shall w s a r is o r h a loid ossa i depressio n calle d th e fo sa patell y f . Op nions diff er as t o wh eth er or n o this fossa is lined by an e xten sion of th e hyal oid a own o e a io o r th e i ws o f u a a th e membr ne . My bs rv t ns c nfi m v e St rt th t memb ran e is c o ntinuo u s ove r the su rfac e o f th e fo ssa . Th e prepara io s o n i i o io is e are n ot e e e e t n wh ch th s c nclus n bas d h r r pr sented , but in 8 e e i t o a th e a oi e e o n No . th r s evide nce o s h w th t hy l d m mbran the i of io is a e o s o i a e w i s left s de the sect n sep rat fr m the uspens ry l g m nt , h l t N 1 0 e to be n e a e o . i o . the sam rrangem nt w uld se m suggested But perhaps th e best de m on stration of th e independe nce of th is l ayer from h u n n i n No w e e it m a be e t e s e o i is i . sp s ry l gament g ve 9, h r y s en i n n a e h e e ara io i i si i th e . o t s d st nctly pas ng beh nd lens U f rtu t ly , pr p t n a e ro a a o o i a e e in is i a o e s n ot invali t k n f m p th l g c l y , but th nstance th t d a h i d te t e proo f wh ch it exhibits .

It is in the ce ntre o f the b otto m o f this s aucer - sh aped depressio n that th e an te rio r extremity of the hyaloid ca n al Open s : h e re it is s om e

- a e n a or i a is o as ost len ta i s ace. wh t l rged , f m ng wh t kn wn the p p A u i n o e of s o of i o i s e e i N . 1 e ggest n th s may p ss bly be n 5 , the y a full t e rm fo e tus . a o a a io o e i th e e s in eri of Wh t m st attr cts ttent n c nc rn ng l n , the s es e i io a s e ion o f th e e e is th e a its o arie m r d n l ct s y , f ct that f rm v s very u th a o o 1 6 an d 1 t o a . N o e o s . 1 m ch As we pass fr m f et l f rm ( 5 , 7) th t i a e in an e i e No 1 an d it is e i e th e e e d spl y d adv c d l f ( s . v d nt that d gr e of co nvexity of th e anterior surface of th e lens displays a m arked reduc i i i n a th e s e i a t on . Dur ng foetal l fe the le ns appro aches mo re e rly ph r c l r e a fo rm ; in th e age d it be c o mes thin ner and o f m ore c omp e ss d sh pe . This appears to be effe cte d at th e e xpens e m ore particularly of it s a e ior s r a i o e a e an ara i is nt r u f ce , wh ch bec m s fl tt ned , appe nce wh ch a i we s in o an 2 e th e ior a o f th e e N s . 1 d p rt cularly ll e n , wher anter spect n h as ra i a e o e a s r a e n er ia o s are le s p ct c lly b c m plane u f c . I t med te f rm is a in N 8 e s n o or is e os. 10 1 1 . a d pl y d 3, 4 , 5 , , and Wh t app ar tew thy ANTERO - POSTERIO R SECTI ONS OF TH E EYE 2 7 that this re ductio n in the an terio r curvatu re tak e s plac e e venly and u i o rou ou an d n ot as wi e e e t o u n n f rmly th gh t , , ll be p r s ntly ref rred , e a as a ea t o e in th e as e o f th e o e ior a e . q u lly, pp rs happ n c p st r surf c If the po ste rio r aspe ct o f th e le ns be examined in all th e ph oto

‘ a s e o i th e exce tio n of o e of oe a gr ph r pr duced , w th p th s the f t l eyes , the ‘ curvatu re of this s u rfac e is always m o re pro n ou nced in th e cent re th an o a th e i e i is a a a a ea a e or du e t w rds c rcumfe rence . Wh ther th s n tur l pp r nc Th e to th e influ e nce of th e h arde ning reagent it is difficult t o say. fact th at th e m o re p ron ounced c e ntral c o nvexity co rre sp o nd s t o th e denser n uclea r a of s i a i e ia a oi i p rt the len , wh lst the fl tter c rcumfer nt l p rt c nc des wi w a is e th e s ubsta ntia cortica lis th e o an d o co m th h t t rmed , s fter m re e s i e ar o ee t o o e in pr s bl p t , w uld s m suggest that the f rms repres nted the o o a s are u n a a an d th e s o f th e i e u i ie ro ph t gr ph n tur l , re ults rr g lar t s p du ced th e a n i i be o it is o o a e ea e . s by h rde ng r g nts If th s a pr f th t , tak n as a o th e is o a i o its i e wh le , lens m re pl st c ar und c rcumference just wh re n o e it is m ost subject t o th e influe n ce of the susp e nso ry ligam e t . An th r feature which se ems imp ortant is th at this circumferential flattening of the posterior surface of th e l e ns on ly affects that part of it which lies i e of th e a a of its n o a i As a o e e o f w d re rm l optical e ffic ency . c ns qu nce the fo rms here d e scrib e d it fo llows that th e equ at o r of th e le ns do es n ot as on e is led to i e o res o to a in s ri oi i i , bel ev , c r p nd l ear t p c nc d ng i th e i of its e i bu t o i e i o e a w th summ t great st w dth , harm n z s w th a s m wh t o and e o i i e th e a a n of br ad flatt ned z ne , wh ch nt rvenes between tt chme ts a e io r an is the nt r d p osterio r l amellae of the suspen so ry ligament . It this zo ne which forms th e inner wall or b ase of th e triangular s pace

i o th e so - a ca nal o P etit e ua tor ial r e ion o f wh ch f rms c lled f . The q g the l ens may th e refo re be de s cribed as th at circ u mferential are a which lies b etwe en th e attachment o f t h e anterio r and p o sterior layers o f the o e of i th e i io of w i on th e of th e le s z nul Z nn , mplantat n h ch capsule n is ar e two e - e e e w i o in m k d by w ll marked dg s betw en h ch , as sh wn ri io e a s ion th e e i i iff e e of i . m d n l ect , l ns exh b ts d erent degr s flatten ng i i i s la in i 2 8 1 0 an d 1 1 . a o o in Nos . 1 Th s d sp yed v r us f rms , , 3, 4 , , 9, In No . a e i of u a o ri e io is o ma i 9 the fl tt n ng the eq t al r g n m st rked, but th s , as h as e a ea is a a o o i i e th e o f be n lr dy stated, p th l g cal spec m n , result a o n o f orn ea ro a o i era io of es w u d the c . It wo uld appear f m c ns d t n th e observations that the influenc e e xercised by th e fibres of the s u sp en . s ory ligament are rather of the n ature of a tractio n th an a pressure effe s i o ou e to as i e th e n e of th e ct, nce the f rmer w ld t nd emph z prese c ri w i i i it in ro n an d e in th e e a oria on e w i s dges h ch l m t f t b h d qu t l z , h l t a re e e ffe e in u o th e i n i i e o au it p ssur ct, squ ez g p n nterve ng t ssu , w uld c se t ’ o bulge u p in to the fl o o r o f Pe tit s canal . Th e en s as a in th e i at m i os a i e s s s l , me sured spec mens y d sp l , g v re ult as fo llows

Th ari m 8 - 0 - i an e i e . to ie e o a i o . quat r l w dth v s fr mm 9 9 mm , y ld ng 28 ANTERO - POSTERIO R SECTION S OF TH E EYE

° h e u a f8 6 . fo r t i e i o e e in a o all. e o ver ge mm ser es , n mb r ng f urt n The ant r po sterio r thickn e ss varies b oth with age an d th e co nditio n of acco m modatio n o to a iff in i , c nsequently we expect find gre ter d erences th s

ea . o th e e ie e r m sure The figures deduced fr m s r s rang f om 2 mm . i a a fo r i e f to . o 02 4 mm , w th me n ten spec m ns 3 mm . The relations of the lens are well displaye d in the ph otographs of i io a e io io the mer d n l s ct ns repro duced . Anter rly the central part of th e lens forms the posterior wall of the anterio r compartm e nt of the aque ous chamber ; th e extent of this surface depe nds o n the size of the area

o e i . a t o i i w i unc ver d by the pup l Extern l the pup llary marg n , h ch rests in o i a io a of o o f c ntact w th the nter r surf ce the lens, the fr nt the lens as far as the attachment of the anterio r fibre s of the zo nule enters into the fo rm atio n of the p oste rior wall of th e posterior came ra of the aque o u s a h of e f ch mb er . T e extent the surfac s o the iris an d le ns in c o ntact i o i n to in o to e n w th each ther s see vary the ph tographs . It seems d pe d o n the degree of tensio n of th e iris and the extent of the curvature o f the e in No 1 0 a of o o s to a . o as . o l ns In s me , , the are c ntact c rresp nd oi of i a i o i iri tan p nt , the edge the pup ll ry marg n , fr m wh ch the s extends en tiall n in No 8 t o a e o a i o s . w s g y utw rds ; thers, as 3, 4 and , the urfaces h v i a i in 2 w r o i o f o a w Nos . 1 t o a w der rea c nt ct h lst and the st uctures , w ng to th e e o f o n of lie a to ea o in os e flatn ss the fr t the lens , p rallel ch ther cl a io In th e a a io i n io of . o rel t n prep r t ns my p ssess n , the depth the io a as a e o e r oi of i er anter r ch mber, t k n fr m the c nt al p nt the nn a e o f o to th e o of i of e surf c the c rnea fr nt the m ddle the lens , m asures

- o 2 t i i on an a of 2 2 . . o . fr m mm 3 mm , g v ng verage a depth mm E quatorially the lens is related to the projecting rounded ends o f the i ia ro e o i it is th e i c l ry p cess s , fr m wh ch separated by c rcumlental

- m h t o 1 1 m . t e i of i t o o 1 . space , w dth wh ch I find range fr m mm ,

i an - i it o is i o e of 1 0 1 . w th averag mm Th s space , be n ted , br dged acr ss n 8 nd are th e o f zon ule o inn i o i Nos . a by fibres the f Z , wh ch , as sh wn 9 ,

i i i two o or - defined a i a w e i subd v ded nto m re less well l m n e , bet e n wh ch

i tit is s o - a is l es the interval kn own as the ca nal of P e . Th called c nal i in e i i io i e i or u in on tr angular m r d onal sect n the nn r s de base , meas r g an a o 1 is o as a t h e e ua tor ia l zon e average b ut mm . , f rmed , has been st ted , by q a o th o io in r und e Circumference of the lens . P ster rly the lens rests the ossa a tellar is of i o o is o i o io f p the v tre us hum ur, and thus br ught nt relat n a e o i c e ntrally to the ante rior extremity o f the hyaloid can l . The quat r al

i f - i i o i o r the o i 2 . ax s the lens l es 4 mm beh nd the l mbus c njunct vae ,

e r - xternal scle o c orneal junctio n . The m o st n o ticeable features in connexion with the foetal eye are

th e large proportio nate m ass of the lens and its m ore sph erical form . o s i er is o e w i o a In c n equence , the anter or chamb shall w r, h lst the f ss a e a i is i n of th e e a o o o s to th e p t ll r s d eepe r . Th e reg o qu t r c rresp nd summit o f th e curve fo rmed by the c oal escence of th e anterior and

30 ANTERO - POSTERIOR S ECTION S OF TH E EY E

To i i e r a e h as e n i e n a e o f th e ca na l o P etit th s nt sp c b e g v the n m f , th e nature of which will b e m o re fully dis cusse d whe n s ome o f th e o o a a e n o i 8 an d o ther ph t gr phs h v bee c ns dered (s ee pp . 4 8 it is wo o n a th e of th e In No . rth n ti g th t p oste rior sheet o f th e fibres zon u le of Zi nn is independ e nt o f th e thin hya loid m embra ne e ncasing d a o i reo as ain s e n o n e i of No . 8 an the v t us , may be f tly e the l ft s de , ls

. i a r in n n e e e on o s i e in No . a o o a i b th d s 9 Th s l tte pr t , lth ugh fr m jur d y , i o u e it i es s o e e a iew of th e on u e has been ntr d ced becaus g v xc llent v z l , o i t o a a th e i is a i o e en to o ea w ng the f ct th t r , h v ng bec me adh r t the c rn , '

h as o ar a i i it th e i i o es e s . In is been pulled f rw d , c rry ng w th c l ary pr c s th n a a i io of h as e th e e u an d th e iri way a tur l d ssect n the parts be n r s lt , s bein g drawn o u t of the way th e susp e ns ory ligam e nt of th e le n s is o a m re cle rly exp osed . Stretching across the circu mlen tal space the layers o f th e su spen sory ligam e nt are seen to interve ne b etwee n the aqueous chamber in o n h it Th e n r o o fr nt a d t e v reous behind . a terior laye of the z nule f rms in a i of th e oster ior ca mera of eo a p rt the h nder wall p the aqu us ch mber, b eing separated fro m the p o sterior s u rfac e of the iris by an interval a i 0 - o o e wa e i i i s . a a verag ng 93 mm fr m bef r b ck rds, a m sure wh ch nd cate th e e o f r r a dis d pth the poste ior Ch amber at this particula p rt . The tance fro m the back of the iris to th e fro nt of the posterior layer of the

o on 1 - i i e n ot o z nule measures an average 9 mm . Th s nclud s nly the

- o e io o s o a e a of i . p st r r chamber, but als the c ll d can l Pet t F or fu rth e r details c oncerning the suspensory ligament see 0 pp 37 , 47 and 5 v i r ou i of i The t e s . Ow ng t o the apparently structureless nature th s o i o f th e e i e e i e of its re ecan be c nst tuent yeball , but l ttl v d nce p senc seen ri in the ph o tographs . Its exis te nce is de m o nstrate d in m ost of the p nts n of a i f i o e e e in it by the prese ce p rt cles o dust wh ch have bec m mbedd d , or by the air bubbles within its s ubstance which te nd t o mak e their appearan ce in the preparatio n s when th ey are being thawed after having cut in o e o i io been the fr z n c nd t n . Th e vitr eous is o in h aloid membrane o e e encl sed the y , the ut r surfac

of which is closely applied to the inner surface of th e retina . Under o rdinary circumstances in these meridion al se ctio ns there is n o evide n ce

‘ to ro i of i e io a as in No . 1 0 p ve the ex stence th s lay r, but except n lly, , the a oi h as o e a o i an d hy l d membrane bec m sep rated fr m the ret na , appears as a delicate filmy structure lying i n fro nt of th e retin a to th e right o f the entrance of the optic nerve ; the de lic ate strands of tissue which o t th e a e a io th e c nnect the wo are distinctly n oticeable . In s m prep rat n hyaloid membrane is s een separated from the surface of the ciliary pro n cesses o th e left side of th e se ctio n . 8 Attentio n has b een already directed to the fact that in N 05 . and 9 the hyaloid m e mbrane h as also be e n sh own as distinct fro m the po ste rio r ANTERO - POSTERIOR SECTION S OF TH E EYE 31

a i a o f th e of the en o i a e n o i it s n s as l m n fibres susp s ry l g m t , fr m wh ch ta d r a layer apa t . o a e th e i o i o e i e of e In the f et l yes , v tre us d splays m r ev denc structur ,

i u in i s - i N 1 th a a e . e o o . e part c l rly the e rl r tages In the full t m f etus, 5 ,

vitre o us h as s hrunk away from th e retina p osteriorly . A su ggestion of a post- lental sp ace in the c e ntre an d at the b ottom of th e patdlgr fossa i i also appears v s ble . In th e foetal eye s o f 6% m o nths the vitreous is trave rsed by layers of film - oo in i an d o n ot a to u ir s a e y l k g t ssue , d es ppear fill p the ent e p c

i in e i . i is o a du e t o i i in th e s i a w th the r t na Th s pr b bly rregular ty hr nk ge . No 1 th e h aloid a rter be e a i o In . 7 y y can very clearly s en p ss ng thr ugh the su bstance of th e vitreous from the o ptic papilla poste riorly t o th e of e s in o back the l n fr nt . F or e ai i 8 n 6 1 a d . furth r det ls c oncern ng the vitreo us see pp . 4 C HAPTER I I DI SSECTION S OF TH E EYE FRO M TH E FRO NT

f i H S i e i o o o o Nos 1 to 2 i n u e . T I ncludes the s r es ph t graphs fr m . 9 3 cl s v These c omprise an illustrative series of dissection s design e d to expo se th e iff r in io to th e a ou s a e d erent st uctures relat n que ch mb r .

1 a io s r a e of i o e . In No . 9 the nter r u f c the glo be of the eye s exp s d The c ornea has been rem oved by cutting it thro ugh alo n g th e lin e

- u i i of t a is e n of the scl e ro c o rn eal j nct on . W de this the scleral conju nc iv s e s itn i a i a e a e it n i , d spl y ng cut edge xtern lly wher has bee sn pped o on i e s of sclerotic ea o f thr ugh ; bey d th s , the ext rnal urface the , cl red i o n its ar a e s s S . muscul att chm nt . h w By the re m oval of the cornea t h e anter ior ca mera o f th e aque ous a e h as e i u re w i o it s os e io r ch mb r b en la d Open , and the str ctu s h ch f rm p t r

“ are o e are i in th e a a of i ou a . b nd ry thus exp s d These , w th re the pup l , th e an erio of th e lens e a to i r i t r surface , and , xtern l the pup llary ma g n , io a o f i r is i i i th e a er s . nt r surf ce the , wh ch here d splayed n e a i No 20 i i h a rie s e a o o . o s In ther pr par t n , , the d ssect n been car d a tag to o th e i r is n e u r s o o a d its a . f rthe , as m re fully exp se ttachments Her th e era i off o th e on of th e e e o i th e scl has been str pped fr m fr t y , exp s ng ou te r s urface of the cilia ry body and chor ioid ; but be it n oted th at in i a a th e ro i a o ri of o i s e th e S O tear ng w y scle t c narr w ng c ndensed t s u , a e a nn ula r li amen t : i is e n w th e i i c ll d g , has been left th s s e just here r s i i o o e o e and is we i a in and the c l ary b dy bec m c nflu nt , ll d spl yed the e of e i e of N 20 r ar e o f th e u pp r half the l ft s d o . wh e e the rangem nt rows it i o ie i i th e r r eri io light th nt rel f. Th s s s t uctu e t o which the m d nal of i iar s e are a e an d it is ro the ro of i fibres the c l y mu cl ttach d , f m f nt th s ridge th at th e fibres o f th e pectinate lig a ment h ave b ee n torn away in i e o i o o e remov ng the scl r t c and c rnea . The reader sh uld rem mber that it is this ring o f tissu e which in micro s c opic meridion al sectio ns of this io o o i o s o s s or reg n f rms the pr ject ng pr ces called the scleral pr ce spur, and that the canal of S chlemm lies immediately to the o uter Sid e of this ri of o i a i ee i o e th e ng c ndensed t ssue , and has necess r ly b n la d p n by o of th e i o er w o f rem val sclera , s nce , as has been stated (p . the ut all ’ a a is o b i i it s i n e r Schlemm s c n l f rmed y the dense scleral t ssue, wh lst n wall is c onstituted by th e l oo se trabecular substance of th e pectinate n ligame t . 1 The ante rio r surface of th e i ri s is well displayed in both N 05 . 9 and 0 In th e a i i in e io i ri a a 2 . o o o h rdened c nd t n , b th these pr parat ns , the s ppe rs i r a o th e u i e it o s oo i o th cke r und p p l , wher f rms a m th elevated r ng cr ssed DI SSECTIONS O F TH E EYE FROM TH E FRONT 33

f i o i a of i s transversely by a number o rad al f lds . Th s appe rance th cknes is due to an actual increase in the thickness of the tissu e of th e iris in i io s io No ma in i io as . th s reg n , may be seen the mer d nal ect n , 4 ; but y po ssibly be exaggerated by the bending betwee n th at part which is in o i th e e and o io i ie i i c ntact w th l ns the p rt n wh ch l s c rcumferent ally, as i e is e a e b t ward in No . shown . 3 Th s app arance furth r enh nc d y hej t S o of th e i i o a illa i mar in i h as thi i l pe r s t wards the p p y g , wh ch a n ch sel i e i of i is e o e and i i a o l ke edg , the marg n wh ch fin ly n tch d , exh b ts narr w 20 to i o i e o No . o black b rder . In , Cl se the pup llary edge, the c nst tu nt o f i i are in oo or a io n fibres the r s seen arranged a fest ned arc ded fash , i i i e and e e io a i i o w th n wh ch , her there , are se n small d press ns le d ng nt th e f th e i i e s toma ta o f stroma o r s . These are r garded by Fuchs as the

lymph canals .

- i i o in 0 2 1 22 o 0 . o o e 5 . S m t mes , as sh wn N and , ab ut 5 mm fr m the pup l a i i i i i i fe oi i e l ry marg n , the r s exh b ts at d f rent p nts what appears l k a e e in i io io in fre edge of tissu . The same may be seen mer d nal sect n 1 it if i i e Nos . 0 a 7 and , where presents the appe rance as the r s wer o o of two on e i a i in i a i c mp sed strata , term n t ng the pup ll ry marg n , th e o ia i i e in m re superfic l layer end ng, as has been descr b d , a free edge i i o in o of the i i i t o a l ttle w th ut and fr nt pup l . The nterest attach ng this particular arrangement is that the po sitio n o f this irregular edge marks th e line of attachment t o the iris of the pupillary membrane i i i io of o in wh ch ex sted at an earl er per d devel pment, as may be seen i ion io in 6 Th e a i a stomata a o e io e No . 1 ll r mer d al sect n . p p y f rem nt n d lie to i e Si e of i a a o i io is the nn r d th s tt chment , and thus pr v s n made whereby filtratio n of th e c ont e nts of the posterior camera of th e aque ous chamber may take place prior to the opening u p of th e o i io n o c mmun cat thr ugh the pupil with the anterio r chamber . The radial folds which traverse the iris are determined by th e o f i i i o io vessels and nerves the r s wh ch f rm the elevat ns between them , as is o in 26 e f No . o dem nstrated , wher the arrangement these structures is i a n o o o i i o io well d spl yed , but d ubt t wards the pup llary marg n c ntract n o o f lds are als present . i of th e oo e o to th e i i W de sm th levated z ne already referred , r s i i of concentr ic olds in i e i i io o f th e exh b ts a number f , tens fi d dur ng d lat n u i o io s o th e o r i i i of th e p p l , and bv u ly pr duced by c nt act o n and wr nkl ng is it i t sues . At s per phery th e iris undergo es a change in its appearance it r r s e e o i i e . and structure su fac b c mes rregular, p tt d , and dep essed In o i o o N 20 2 in i o os . 1 6 the acc mpany ng ph t graphs , 9, and , wh ch the c rnea a a o it i be o i i i and scler h ve been rem ved , w ll rec gn zed that the C l ary attachment of the iris c orre sp o nds t o the botto m of the ir idial o r ltration a n le i io wi i i o . it s o fi g As w ll be seen , c nnex n th the c l ary b dy i i e i t o i i of a i th e i l es mm d ately the nner s de the annul r l gament , r ng of o n i u c densed t ssue which on meridional sectio n forms the scleral sp r . 1234 C 34 D I SSECTION S O F TH E EYE FROM THE FRONT

a in in i o io of i i t Be r g m nd the c nnex ns the pect nate l gamen , as have been

d escribe d (s ee p . it will be obvio us that the inte rnal fib res of that e a on to i e e of th e i i i e structur , as they p ss the c rcumf r nce r s, w ll hav e or in o a of o e o ne o be n t n the rem v l the c rn a , and w uld expect e i en e o f i as ma be in No 20 s . o e of th e o v d c th s , y seen , where m t rn e of e are i i is i s i i th e nds these ruptur d fibres d st nctly v ble . "u t w th n a nn ular li a ment are a o f c ts ori e of i i e g number ryp , the fic s wh ch are nt r s e cted r of i io i o e by a numbe del cate fibres . The depress ns nt which th e s o e in No 2 i o e o as o . 6 to crypts p n c rr sp nd , may be bserved , the ntervals t e a io of e is o be we n the elev t ns caused by the bundles vess ls . It thr ugh s o e i cilia s tomata of i i in o r these crypt , s m t mes called the ry the r s c nt a i io to i o i e t o io d ct n the pup llary pen ngs alr ady referred , that the anter r chamb er c ommu n icates with the spaces o f F ontana which are disposed arou n d the bottom an d o uter wall of th e filtra tion a ng le. e a i a ion of e ior of i i as is in An x m n t the ant r aspect the r s , d played o o a 05 1 20 21 26 o a i e of th e i i ph t gr phs , N . 9, , and , pr ves th t th s surfac r s e i i on i a e iff in iff i i i ar ro the xh b ts c s der bl d erences d erent nd v duals . Ap t f m io o f i n it i e e in N 2 h e io a b a o . 1 t e quest n p gme t, w ll se n th t ant r r surf ce a s o an of o e e ei appe r much m re rugged th any the thers , th r b ng several a s io on it e of i are S and l rge depre s ns , the edg s wh ch harp well defined ; e t oo ea i i e is an i r a o th e h re, , n r the pup llary marg n th re r egul r b rder, a i of i ea an d o in i ar a m rg n wh ch app rs free utstand g . Th s r ngement has

n to No . 26 o of i i is o bee alluded already . In the fr nt the r s sh wn as wi to f i en i o a . a o much m re regul r O ng the bsence p gm t , the rad al Th e arrangement of the vess els and nerves is well seen . crypts at its i iar or n ot so an d o c l y b der are well defined , but here there the t rn fibres of the pectin ate ligament are indicated by the woolly appearance i a t o is mp rted th edge . In No 2 th e i e io i a o of . 4 d ss ct n has been carr ed f rther by the rem val o n e In r ca mera of o h alf of the iris . this way the posterio the aque us er h as ee i o e re o a of its e io r chamb b n la d p n by the m v l ant r wall , thus e o i o ior o n fully xp s ng the structure s which form its p ster b u dary . "iewed in the ste reo sc ope the right sid e of the ph o tograph displays the a e ior s f u a i o f nt r urface o th e lens n ow fu lly expos e d . A small q nt ty pigm e nt clo se to the pupillary edge of th e divided iris Sh ows where r t that structure h as rested in c ontact with the le ns . The ci cumlen a l

S is e a a i o . o i i in pace r ve led as dark r ng r und the lens Cr ss ng th s, r i a a io th e i a of zon ule o i nn to . d al f sh n , del c te fibres the f Z are be seen Wh e re th e se are attach e d to th e len s capsule they impart a cre nate d a a a e to i r o e o of i f . ppe r nc the c rcumfe ence the l ns In fr nt these , wh ch or a io a e of s us enso li a ment of a o f m the nter r l y r the p ry g the lens , and b ut

- 0 . ro th e i of th e e be e th e o no 5 mm f m per phery l ns, may s en r unded k b i e e re i ie of th e cilia r ocesse e rio to e are e l k xt m t s ry p s . Ant r th se a numb r of i ro i i - e are e dis o o e s . th n , p ject ng, l ght c l ur d fold Th se ev n better DISSECTION S O F TH E EYE FROM TH E FRONT 35

in o 2 i i i a . is played N . 5, where the ent re r s has been taken aw y It evident th at these folds have be en divided when the iris has been o e an d o e l one o to i of i rem v d , c ns quent y w uld expect see ev dence the r o i i o n a of i i e in c nt nu ty the b ck the r s , as may be seen , here and ther , 2 i i to S a o o e o to No . s 3. It d fficult y whether these f lds c rr sp nd the i ia o or r a e i "Th e a ear c l ry pr cesses , whether they alte n t w th them pp ance displaye d would seem to indicate that they we re a forward ei i a o i i extensio n of these processes . Th r number s ppr x mately s xty i t o s i o i i o a o i e ght eventy, wh ch w uld br ng them nt h rm ny w th the of i i r o in o o i e i number C l a y pr cesses the c rresp nd ng sp c men . The prese nce of these folds must cut up the po ste rior came ra into a series o f o a n s o r e o i to i w c mp rtme t c r sp nd ng the ntervals bet een them , and th ose wh o deny the existence of a posterio r chamber will have to acco unt for the disappearanc e of thes e interspac e s by the c ompressio n of the folds against the anterio r surface of the lens and the proj ecting o e of i i o f r parts the c l ary pr cesses . n ow to i os e io f th e i i i It may be well exam ne the p t r r surface o r s . Th s i e in i n 2 n t th s o a a r i ow i o . wi e xp sed the sep r ted s sh n N . 3 O g o deeply i o i io of is i o f i i it is e re e i to p gmented c nd t n th s de the r s , xt m ly d fficult get

a o o a of it i i S o u ai . i r a ion ph t gr ph wh ch w ll h w p the det l In th s p ep rat , o er e an d o a of of i i is h wev , the flut d f lded rrangement the back the r s i i i i o 6 a a a e o e s a n N . f rly well seen . The ppe ranc , h wev r, better d spl yed 4 , iris is r i n itu a i c rona cilia ris re e e s o o . wh re the rep esent d l ng w th the He , o i to e i io of o i o f ro e its u a w ng the bl ach ng act n per x de hyd g n , struct r l r details are better displayed . Aro u n d the pupillary margin the e is a o 1 in n i o rio of th e i i is o . i i z ne ab ut mm w dth , wh ch the p ste r surface r s ro i n o i f i o i of th wn t a ser es o very fine rad al folds . These verl e the part i i in i i of i is and o the r s wh ch the sph ncter muscle the pup l placed , f rm o t t exami the c n rac ion folds of the pupillary zo n e (Schwalbe) . A careful io of i n 2 i o i i a i No . nat n the pup llary edge , as d spl yed 3, w ll pr ve that th s r i is not e o i i i i ma g n an ev nly fl w ng l ne , but exh b ts a crenated appear ance due to the proj e cting ro unded ends o f these fine folds . i of i ar tr uctural olds of e o e No . s W de the pup ll y z n ( the f Schwalb , o o o in o t o i o ar o much m re pr n unced f rm , are seen rad ate utw ds t wards the i ia a en of i i e o i i i C l ry att chm t the r s , where th y b th w den and deepen , g v ng to i o f th e i i a a ra is e o s i th s aspect r s ple ted appea nce . It th se f ld wh ch we have already n o tic e d in a divid e d c o ndition in th e disse ctions where th e i i e e o No 2 and r s has b n rem ved ( s . 4 i a io in N 6 i n ot i t o th e concentric The magn fic t n o . 4 s suffic ent reveal olds ri e o om u s ion of be f desc b d by Fuchs , th ugh s e s gge t them may r - r e cogniz e d in the right h and l ower quadrant of th e i is . Th e i e iris measure s o n an average 1 1 mm . in diamet r ; the d ameter

f th e - i n o i o . m in a o . pup l ranges fr m 3 mm to 5 9 m . my prep rat s F or o 1 an d . ther details in c on n exio n with the iris see pp . 3 43 c 2 36 DISSECTION S OF TH E EYE FROM TH E FRONT

Returning to a further e xaminatio n of the disse ction d isplayed in it i be e a s o i a i e e i No . 20 s , w ll se n th t , urr und ng the annul r l gament , th r

- i o 2 in i th e o a i o o e o . e a e l ght c l ur d C rcular z ne ab ut mm w dth , c nv x surf c o i r fi ne ff a a a e is is th e o er s u r a e f wh ch p esents a flu y ppe r nc . Th ut f c of ci lia r b od o e o i to th e e e a o o the y y, and c rr sp nds d rectly xt rn l p rtio n f e i io n o f i i u s e a it h as e the m r d al fibres the c l ary m cle . Ext rn lly, b en i o h as e o e . si to is separated fr m the sclera , wh ch b en rem v d Pas ng th o ma s o f th e ciliar n er ves o e e i z ne y be seen the filament y , t g th r w th branches fro m th e a n terior and long poster ior ciliary a r ter ies . i o f i i i o e th e o of ch ori oid is e o e W de th s c l ary z n uter surface the xp s d , overlain by some o f th e ciliary nerve s and e xhibiting the wh o rl - like e of a i e of th e orti cose veins In No 2 arrangem nt the r d cl s v . . 5 a further dissectio n of this region h as been displayed in this prep aration ; th e tiss ue comprising the ciliary muscle has been stripped off o n the left i of h e o cu t of is hand S de t ph tograph . The edge the muscle seen i e i at the right and lower corner of the preparat on . Her the t ssue re moved includ e s b oth the mer idiona l and circula r fibres of the ciliary muscle as i h as a - i a i , but the str p been pulled way, an ever ncre s ng number of the circular and finally some of the radial fibres have re mained i n s itu so th e i io o o to e e of th e , that trans t n fr m c mplete absence pr senc e i is o ma o i a i i nt re muscle a gradual pr cess , as y be rec gn zed by ex m n ng of i o io of i o is the upper part the preparat on . A p rt n the str p rem ved

in . an i "i of ciliar seen stretched ou t No 66. It gives adm rable ew the y plexus (plexus g angliosus cilia r is) formed by the splitting u p of the i ia e o o a i a i an d i a e C l ry nerves . The sam ph t gr ph d splays th n del c t i o it i i in a e o ie membrane wh ch , fr m the fact that l es w th the pl n ccup d by the Ciliary nerves and has been re move d with out carrying with it e of a o ioi e ar e as la mina any trac the vascul r ch r d , must be r g d d the s u ra chor ioidea a oi of o i e as i o a to p , p nt s me nter st, th s w uld appe r s uggest that s uch may be the main inse rtio n of th e meridional fibres o f i i s the c l ary mu cle . Return ing t o a furth e r c onsid eratio n of th e disse ctio n displaye d in N 2 i i f o ic s o . t be o a o e o th e rb ulu 5, w ll bserved th t the uter surfac and corona ciliar is has b e en e xpo sed by th e rem oval of the ciliary

. i e e i is o o e in lowe muscle Th s, as has b en xpla ned , m st c mplet the r of th e r i o o i a e e in o io part prepa at on . The m st n t ce ble f atur c nnex n with the s urface thus exposed is th e fact th at th e vessels of the o ioi now x i i e i o f u ch r d , as e h b t d , d splay an arrangement parallel b ndles i io in i is osi io o i i a a o f mer d nal the r d p t n , thus c ntrast ng w th the ppear nce o i o s e o the v rt c se veins which lie wide of the Ciliary zo ne . The gr ups of vessels appear to c o rre spond with the pos itio n of the cilia ry pr ocesses i lie i wh ch nte rnal to them . o o e e i i e to th e e o f If the ph t graph (No . 25) b examin d mmed at ly l ft th e cut e e of th e i i e th e e o w i t h e s e dg c l ary muscl , surfac fr m h ch mu cl

38 DISSECTIONS O F TH E EYE FRO M TH E FRONT proving the e xiste nce of a space betwe en th e structure which throws th e Shadow and th at o n which it falls s o me of th e fibres o f the zo nule th e a o lie clearly in fro nt o f sh d w . i No 8 i No . 2 a a o . 2 o i io In 9, the s me prep rat n as , v ewed by a c mb nat n o f a i e e i ri of o are ain tr nsm tted and refl ct d l ght, the st ae the z nule but f tly o io o oo of No 0 i is represented ; the same bservat n h lds g d . 3 , wh ch f a io i i i o a ph otograph o the s me preparat n v ewed by transm tted l ght nly . No 1 e i of is o In . 3 an nlarged v ew the same structures sh wn ; the o ai i to is i i o at th e nly det l wh ch need be referred , that the c l ary pr cesses lower part of the preparatio n cast a shad ow on the fro nt of the zonule in it o i such a way as to suggest that forms a c nt nu o us membrane .

N 2 f i - o h a e i o . ro o o s 3 , f m the eye an e ghth m nth f etus , been tak n w th

a co mbinatio n of reflected and transmitted light . The fibres of the zonule o u i o io i e is e oi of i sh w p well , but the r c nnex n w th the l ns d v d the sp ne i o o in e i i o e t o l ke pr cesses s comm on the adult sp c mens . Th s w uld s em point to the fact that the o ccurrence of these irregularities in the circumference of the lens in th e adult is associated with th e traction effe cts exercise d by the fibres of the zo nule during the practice of o o i i e i f acc mm dat on . N ote the greater anter or c o nv x ty o the lens as o i c ntrasted w th the other preparations . F or r t o th e o i . 1 2 fu ther references suspens ry l gament see pp 3, 9,

47 and 50 . e i The Len s . In th e various preparations which have b en stud ed th e io a of is in a or in o o e i i anter r surf ce the lens , p rt wh le , exp s d exh b t ing in divers fo rms the appearance of the lens stars under different o i io f i e io o i . No 20 as o c nd t ns l ght In . , seen thr ugh the pup l , the ant r r s a of th e i i o of o e i urf ce lens exh b ts a star f rm , r sett appearance , w th five

e a in N 1 a - a e i p t ls ; o . 9 n indicatio n of wedge Sh aped m sses me t ng at e is s i in N 26 i i io of s the c ntre uggeste d ; wh lst o . the d v s n the len by

tri - a ia e i io s a r d t ser es of dark lines is clearly se en . In the preparat n w e a e io r e of e is i e o a o her the nt r r su fac the l ns ent r ly exp sed , d rk , narr w, we dge - shaped masses are displaye d : these vary in numb er from ten

t o i n . Th e o f i are of o n o th rtee bases the wedges, wh ch r u ded f rm , a o i e i i a i are i e to th e ppr ach the c rcumf rence , wh lst the r p ces d rect d f N 2 o e o Nos . 2 2 28 2 o . centr the lens (see 5, 7 , , 9 and In 3 , fr m

th e e e of an i - o o e are not a e y e ghth m nth f etus , these wedg s reve l d by differences i n tone here the front o f the lens is traversed by four dark

i w i i n H - a io in e of th e l nes , h ch meet shaped f sh n the c ntre lens, and i i it u i o o s d v de p nt f ur unequal part . In m o st o f the preparatio ns the fro nt of th e lens retains so m e of the iri i i o n it i i i e of o a of th e i d al p gment , mark ng prec sely the l n c nt ct pup l a i at ti f e l ry marg n the me o d ath . R e fere n ce has been already made to the irregular appearance of the

i e - i a e of C rcumferential margin of the l e ns . The tooth d l ke rrangem nt DISSECTION S O F TH E EYE FRO M TH E FRO NT 39

th e e dge h as b ee n e xplain e d as evid e nc e o f th e strain exercis ed on th e h f th e e f zo ul To i a cap sule by t e tensio n o fibr s o the n e. th s arr ngem e nt f i n n iz a o th e oe i n . e e s o e io v . e e o e e th r except , th t f tal sp c m (N wh r th e i e e e o f e e i i s i e an e e e du e o a c rcumf r nc the l ns xh b t qu t ev n dg , pr b bly to th e fact that it h as n ot be e n s ubj e cte d to th e strain e xe rcis e d on it a re e e o f o i o t e— n ior during cc omm odatio n . The g at r degre c nvex ty f h a ter a e of th e oe a e h as e a a a to surf c f t l l ns b en lre dy lluded . F r i o e i th e s ee 2 n o o e e a a d . th r d t ls c nc rn ng lens pp . 5, 45 49 C HA PTE R III ANTE RIOR HALF OF TH E EYE SEEN FROM BE H I N D

H i e s f w i i i S ie o o o a Nos . to T I nclud the ser s ph t gr phs , 33 47, h ch exh b t th e arrange ment of th e structure s within the ante rior h alf of the eye as o e i o e a i i in o ia seen fr m b h nd , the gl b h v ng been b sected the equat r l e plan . n a oa of e e are s i i e o si e i Exter lly, the c ts the y een d v d d ; ut d l es the

- s clera is a i an a i s in i i io of 0 . , d pl y ng verage th ckne s th s s tuat n 53 mm Not unfrequently th e per ichor ioida l spa ce is reveal ed by th e s eparatio n ri i th e s er a n 0 n h is s u e i in o f th e o o o a s i 5 . a d t e ch d fr m cl , N 33 34, t wh ch t erve nes n e i i in o two i a o f i e a betwee th m be ng spl t t lam n , wh ch the ext rn l , la mina usca a r to th e i e n a a e o f th e a and i a the f , dhe es nt r l surf c scler , mp rts t o it its i e a a i th e i e a s u ra chor ioidal p gment d ppear nce, wh lst nn r l yer, the p membran e e ai s i e t o e rn u a of th e a , r m n un t d the xte al s rf ce vascul r i i Th e i i i e e two a s is ea e wi ch o r o d . t ssue wh ch un tes th s l yer perm t d th lymph spaces and traversed by the cilia ry ner ves and the long ciliary

th e h as a of i lie In No . 47 sclera been Cle red all the structures wh ch within it its inn er surface is irregularly pigmented owing to th e adher f ro its io i o n is s e e o i . nc the lam na fusca In f nt un n w th the c r ea een , a n d here a goo d demonstratio n is give n of th e groove (s ulcus circula r is cor n a e i inter nal - n l tion e e) which lies immediately b h nd the sclero cor ea junc . i ai i e th e io s oo e h as e . s o o Th gr v , as been xpl ned (p f rm d by pr ject n o f ir u e e of o i r a an d in o i its the c c mf r nce the c rnea nte n lly fr nt , wh lst o ute r wall is fo rmed e xte rn ally and behind by the inner surface o f the o e ai ectina te li a ment i be it e e o sclera v rl n by the p g ; th s , r member d , f rms o f t l a ti n a n f a t i ha r Th e i the uter wall o h e fi tr o g le o th e n er or c mbe . p g men t ed in e a e o f e a e r in ro n s wi e o f n r surf c the scl r nds ab uptly f t , ju t d

ir ar s in a i - o o e e - defin ed it is o is the c cul ulcus , l ght c l ur d w ll edge fr m th a n n ula r li a ment to i th e cilia r muscle an d th e i r is are that the g , wh ch y a a e h as n r o in i i ia o and it is a o tt ch d , bee em ved detach ng the c l ry b dy, l ng this margin th at th e fibres o f the pectina te lig a ment passing to th e fro n t of i i wi e o a o Th e canal o S chlemm i ies the r s ll hav been t rn cr ss . f , wh ch l immediately in fro nt o f the light zo n e wh ich indicates th e po sitio n o f th e a i e i in o a i i a e ai o e e annul r l gam nt, w ll , all pr b b l ty, h ve b en l d pen h r and e in th e o of th e i s e io it is too i to e ther c urse d s ct n , but m nute be s en in th e e a a i o pr p r t n . F or u e r ai s f rth det l regarding the sclera s ee pp . 7 and 53. i f n N Occupy ng the centre o the preparatio ( o . the inner surface ANTERIOR HALF OF TH E EYE SEEN FROM BEH I N D 4 1

h i of th e corn ea is o e . as e t it o e at ts exp s d As be n sta ed , bulges s m what Circumfe re nce so as to tak e part in the form atio n o f the groove which

s urro unds its periphery . Th e b ottom of the groove is a ngular and fo rm s a crisp furrow which on meridio nal s ectio n appears as a d e finite kink

‘ i a th e o i io of th e internal s clera- cor neal unction an d it is th s m rks p s t n j , e in o of re arfition vh e re it her , seen very clearly the l wer part the p p fi ’ as a ar i e e e i o appears d k l n , that D scem t s membrane , wh ch c vers the i e s r a e o f o ea a a its r e u nn r u f c the c rn , bruptly lters cha acter, and br aks p i o r e i of ectina te li a ment th e o e a of nt the t ab cular t ssue the p g , ut r surf ce i is e to th e e e a a a th e canal o S chlemm wh ch relat d xt rn lly pl ced scler , f i n Th e i e u is e tervening . rr g lar appearance d play d by the inner surface ’ of the c orn ea is due to th e wrinkling of Desce met s membrane unde r the i u of th e e i a nfl ence hard n ng re gent . F r i i to o e o s e e 8 . further d ta ls relat ng the c rnea p .

Th e Ch ori oi d coat . In th e m aj o rity o f the preparations this layer can be s e en distinctly at the cut edge of the sectio n as it lies between th e s cl ra r a a r ti a eti a o e e exte n lly and the p s op c r n e internally . I n s m instanc es it is separated fro m the sclera by th e op e ning up o f th e er ichor ioida l s ace in i o i io it has o i it r p p , wh ch c nd t n verly ng exte nally the s u ra i ra o o f th e re p chor oidal memb ne (see N os . 33 and In ther p paration s it h as separated fro m th e nervo us layer of th e pars optica be it o its i e e e i ae in Nos . r t n , as 35 and 43 but here n ted that nn r surfac is dark in colour owing to the fact th at th e pigment laye r o f th e retin a is i a to it a io a e a e o e n ot e st ll dherent . The sep rat n t k s pl ce , ther f r , betw en chor ioid o e and r eti n a e th e o the pr p r the , but betw en nerv us and

i a i o n . 1 i s of as has a 1 . p gmented layer the ret n , been fully expl ned p i o e i i chor ioid as it L ttle m re ne d here be sa d regard ng the , has been d e scribed at length in Ch apter I (p . a erio io of u veal coa t as s o wi i now The nt r extens n the , een fr m th n , may be o i e o it o be ea er oo a in o of th e c ns d red , th ugh sh uld cl rly und st d th t fr nt ora serr a ta of the pars optica retinae it is overlain internally by the pars cilia r is and ars ir idica retinae w i i to it its i e n e a a p , h ch mpart p gm t d ppe r a e o n f h e ora s a nc . In fr t o t errat there is a fairly sm o oth circular

i e a - in i o o 6 . i i i a a a e e p gm nted z ne , b ut 3 mm w dth , exh b t ng the ppe r nc , wh n th e i o s is in osi io o f ain a ia s ri i N and o s ee OS . v tre u p t n , f t r d l t at n ( 33 is is orbi cu lu s ci lia ri s r th e r o a of th i e Th the . Afte em v l e vitre ou s th s ar a can be m ore readily examine d it will then be o bvio u s th at th e striatio n is du e to th e disp osition o f th e vesse ls which are h ere s ee n running radially from the ciliary processes in front towards th e ora se rrata are th e i of i ia r behind . These ve ns the c l ry p oc e sse s which are passing

a to ai i o vor tico vei s . i o e n N se n i o . backw rds dr n nt the As w ll be bs rved 37, o of e of th e e e a i e o i ia ro e es o s me the larg r v ss ls r s fr m the C l ry p c ss , thers a a to i in e In wee . th e a e io ppe r beg n the vall ys bet n them s m preparat n , and a o in No . 6 o of of o o f i t ls 3 , s me the fibres the z nule Z nn are seen o 42 ANTE RIO R HALF OF TH E EYE

arise from th e tissu e overlying the fo re part o f the orbiculus; imm ediate ly behind th e inspri ng of th e ciliary pro cesse s : these appear as t en s e d e licate glistening strands which require careful focusing and go o d i to S o l ght h w th e m . W i i th e i i co ron a cili ri s o o of th e i ia th n o rb culus l es the a , c mp sed c l ry 6 e i a a f e e o s i a in o to 8 . o pr cesse , wh ch v ry number fr m 7 4 Th y mp rt g f r d a ea a e to is a of i i o and e o s and pp r nc th p rt the c l ary b dy, str tch f rward i ar o i e e e of th e o hi o e nw ds t wards the c rcumf r nc lens , fr m w ch , h wev r, a e ir ml tal o a e they are sep rat d by th e c cu en space . These pr cesses me sur

n - i 1 o n a 2 i e . o e o 0 . averag ab ut 5 mm w d , and r se mm fr m the surface .

Nos . 6 an d ci rcumlen tal In 35 , 3 37 , the space appears as a dark i i e ia o in a e a i io in th e r ng mm d tely surr und g the lens , and c reful x m nat n ste reosc ope reveals the presence of faint radial striae crossing it : th e se are e of th e zon ule o in n i of th e circu mlen tal the fibr s f Z . A better v ew space is obtained wh e n the c orn ea and iris h ave b e en c ompl etely re m oved ro o of e e if e a io be i e f m the fr nt the y ; then , the pr par t n v ew d by a o i io of and i e i th e i a S a c mb nat n reflected transm tt d l ght , c rcumlent l p ce a a i i a o e i th e o e io ppe rs as a l ght r ng r und the l ns , wh lst r und d anter r extremities of th e ciliary proce sses as well as the fibres of the zo nule

i Nos . 0 are better d splayed (see 39, 4 and ' The cili a ry p roce s s es c onsist of upstanding folds c o ntaining a number o f o o i n i i e io a o is a o r e t rtu us vessels the r nt r r ; e ch f ld later lly c mp ess d , an d th e of th e o i an d o i e r o free edge f ld , th ck r unded , r s s g adually fr m o e a of o i n vi i e the f r p rt the rb culus , and , ge tly cur ng nwards , nds abruptly by a rou n ded extremity which proj e cts into th e poster ior ca mera of th e a u q eous cha mber imm ediate ly behind the ciliary attachm e nt of the iris . e e foldS t o o f 0 o r 80 e i Si in ia Th s , the number 7 , are plac d s de by de rad l s io s o a e o o i i of i e e or fa h n , th t ther are a c rresp nd ng ser es nt rspac s valleys

between them . In their appearance an d arrange ment they display c onside rable i i an d d ffe renc e s . In s om e th e free edges of th e folds are fairly stra ght

e a No . in o Nos an d 0 e i e u a an d r gul r ( thers ( . 39 4 ) th y are rr g l r

or o . th e o e a it is n ot u o o to i an t tu us On th r h nd , nc mm n meet w th a e e i n as a e i i No . in w i rrang m nt such th t xh b ted 43, h ch , between each pair of pro cesses (which i n this case number about th ere are subsidiary folds occupying the valleys ; th ese are n ot s o large as the a o o e o a e are air o i and wel m j r pr c sses , but , th ugh sm ll r, f ly pr m nent l

d e fin e d . Th e se have been named th e cilia ry folds to distinguish them o th e cilia r r fr m y p ocesses . When the l e ns is i n s itu the fibre s of the zon ule of Z in n pass fro m it a r th e i r c r cilia r is In c oss c cumlental space to th e regio n o f the o ona . e re a i d th e a an e of es e e o s 05 . an s veral p par t n (N 37 , 39 rr g ment th fibr s

and their relatio n to th e ciliary processes are well dis played . AS h as SEEN FRO M B EH I N D

e e sai o e of s i o th e oe a o f th e o i s b n d , s m the fibre spr ng fr m f r p rt rb culu be i th e o i io o f th e i iar o s e a o ri aris e o h nd p s t n c l y pr ces s , but the m j ty fr m

h i h r n i e io of No s . t e ciliary bo dy in the reg o n o f t e c o o a. An nsp ct n 37 and 39 clearly dem onstrates h ow this take s place : th e fibres take th eir o rigin fro m th e s urface of th e ciliary b o dy in th e intervals or valleys

e e i i o n ot o th e o s es thems e s . b twe n the c l ary pr cesses , and fr m pr ce s ely e a a to ri o ea a i o for As sev ral fibres ppe r sp ng fr m ch v lley, th s acc unts the appearance displayed by the z o nule as if the fibre s were gro upe d in bundles . i e io i i o o f e A further d ss ct n , wh ch enta ls the rem val the l ns and the i i io o f s s e o i o e o e i i d v s n the u p ns ry l gament , c mpl tely exp s s the c l ary o e of th e o n a t a of i ri s pr cess s and exhibits the relatio n c ro o the b ck the .

i h in . h as 6 . N and t e e o Nos . os Th s b en d ne 43, 44 , 45 and 4 In 44 45 darker c olo ur of th e back o f th e iris c o ntrasts with the lighter tint of r f i i h a o o a. r io o No 6 s o o s the c n The prepa at n , wh ch . 4 a ph t graph , e to i io of o i of o i been subj cted the bleach ng act n per x de hydr gen , wh ch , io o o it th e i o cur usly en ugh , alth ugh has extracted all p gment fr m the e io of o o a o n ot e ia to a ff th e r g n the c r n , d es mat r lly seem h ve a ected

a o f i i No 6 th e i i o es are au i S o . uve the r s . In . 4 c l ary pr cess be t fully h wn Their summits are d evoid o f pigment : this is n ot an uncommo n appear o i e on o i io h a o of th e ance , and cann t be expla n d the supp s t n t t the rem val vitreous and hyaloid membran e has e ntailed the l o ss of s uch an am ount of i ma a to for e i p gment as y have dhered them , the sam unp gmented c o nditio n along the summits of the pro cesse s maybe see n in specimens h e t e i r n a No . 6 wher v t eous has ot been taken aw y (N o . In 4 the processes clearly display th eir vas cular structure by the t ortu osity which th ey exhibit on th eir surfaces ; this is we ll Sh own o n th e right Si e of a io n e i o th e o o of o d the prepar t , wher , emerg ng fr m r t each pr cess , may be s een a ve ssel of c onsiderable size pas sing b ackwards into the or i b culu s . Th e preparation also sh ows that the tissue underlying th e a e e e o s is i i i o o s s as v ll ys b tw en the pr ce ses l kew se beset w th t rtu us ve els , th e i i i n h r i er ai o of rregular t es o t e ove ly ng surface prove . A c t n am unt fluffy tissu e may be se e n floating in th e fluid overlying the pro c e sses (the preparatio n s were ph otographed u nd er fluid) : this is the rem ains o f zon ule i a r e is e i i i th e the , wh lst here and there st ay fibr se n , nd cat ng a e of r n tur that st ucture .

No . i i a ie w the a io i i of i ia In 44, a s m l r v , nter r extrem t es the c l ry proc ess es exhibit wh at s ee ms to be a de fle ctio n o f th e pro cess to o n e o r

o e i i ar i to it a - a ea a In th e ea e th r s de , mp t ng club sh ped app r nce . bl ch d e a a io th e ro e e s ei re e e are pr p r t n (No . p c ss s th e ms e lve al ong th r f e dg air e e e r on ei s i e s and in th e a e e we e n f ly v n and r gula , but th r d v ll ys b t , own i th e cilia r olds ma a e e e n rio d wh ch y f y be tr c d , th y pr sent a te rly a i e an d o e o e a e ma el een on th e i p tt d h n yc mb d ppearanc , as y be w l s r ght i e of the a io re o in of cil a s d prepar t n . These a d oubtless the pen gs the i ry 44 ANTE RIOR HALF O F TH E EYE

la nds o f o i s an d be it o e a ei o s i io in In o n as g C ll n ; n t d th t th r p t n , ly g fr t , e do of th e h aloid membra ne of i e o i i e eir th y must , y the v tr us , w ll d r ct th s e re io s i o th e oster ior ca mera o f th a e a th e c t n nt p e qu ou s ch mb e r . At lowe r part o f th e preparatio n a few s cattered fibres o f th e zo nul e re e a i i o a se n r s ng fr m the vall eys . F or i 2 i ia 1 . o i o s ee . further deta ls c ncern ng the c l ry pr cesses , p o of th e an io e e i i of th e i ia o e at o In fr nt ter r xtr m t es C l ry pr c ss , but s me i i o i e as i i a e S a ow l ttle d stance fr m the r fr e ends , nd c t d by the h d s they th e i o erio u e cast (see r ght side o f th e ph oto graph No . the p st r fl t d

s urface of the i ri s can be seen : this h as been already d es cribed (s ee p . o e e th e ciliar rocesses are o w a In the f etal y at term (No . y p s me h t

m ore club - shaped and n ot s o c ompressed ; their anterior extremities lie closer to the len s S O th at th e ci rcumlental space is n arrower th an

i - n th e a u . 2 f n e i o o the No . o e e o a d lt In 4 , fr m the y ghth m nth f etus , ciliary pro cesses are sh own in s hadow an d the circumlental zone a s as i i ou e th e o a and iris a i e ppear a l ght r ng ar nd the l ns , c rne h v ng b en re m ove d and a c e rtain am o unt o f refle cte d light h aving be e n used in a i th e o a i i o e s at i t k ng ph togr ph . The c l ary pr c sses appear quare the r e an nds d m ore irregular in fo rm . T n n in o a a io s h e R etin a . The inter al coat is best see th se prep r t n n i i s t i or e o 05 . a d e th e i e o is s n i u ( N 33 34) wh re v tr us t ll , the nner n rv us

layer o f th e pa rs optica is s een as a pale - grey translucent layer lining i the inner s urfac e of the glo be as far fo rwards as the ora s er ra ta . Th s i o i to th e i ie i n e i e is n ot s o marg n , w ng structures be ng v wed persp ct v , i e as in e i io a e io i s i of its well d splay d the m r d n l s ct ns, s nce the well ng e e to o o o i io i e i dg , due the edemat us c nd t n nduc d by the harden ng

r a en or o - o e a o th e a i i a e g ts p st m rt m ch nges , bscures m rg n wh ch m rks i ea the definite transition of th e pa rs optica to the pa rs cilia r s . In ch o f o o a ow e o n e s i e o the ph t gr phs , h ev r, the l ft de , the crenat d b rder of ora e ra ma be e and o th e i of o of the s r ta y s en , fr m summ ts s me the

s pin e - lik e processes a light - co l o u re d s le nd er thread may be observe d

p as sing radially o ve r th e surface of th e o rbiculus (s ee als o No . In th e preparatio ns wh e re th e vitre ous h as been rem oved th es e a ea e are n ot S o i e a ai amou of i o s pp ranc s well h wn , s nc cert n nt the v tre u , o e e i its oi a e e ai a a e to th e t g th r w th hyal d membr n , has r m ned tt ch d i r s a e h a a i s o e at th e of e i a . In all t e o nne urf c the r t n prep r t n , h w ver , cut edge o f the s ectio n th e retin a is exhibited in such a way as t o e o a e its i is is e a s e dis d m nstr t div s io n in to two layers . Th p rh p b st a in N o th e i e e o . e th e i o s no on s pl y d 43, wher v tre u l ger upp rts nn r la e in o i io and e e a a e i is e i e o i e y r p s t n ; h r th t l y r, wh ch nt r ly c nst tut d k i e e of e o e is o n a a e o th e . dar n rv us elem nts , sh w sep r t d fr m p gm nt d a w i i s e a to it w i h as e i e a to th e l yer h ch l e ext rn l , and h ch r ma n d dherent i e e of th e i a s in e nn r surfac ch o rio d . The s me may be een lesser degr e in N h t o a e s is oi s os . an d th e io of t e w 33 34, where separat n l y r , at p nt

46 ANTERIOR HALF OF T H E EYE or ten processes radiating from the centre and gradu ally.tapering until they reach the circumference ; the angular intervals be twe en these s pokes are o ccupied by folded lam ellae arrange d like the sid e s o f a G o i ar th e s i of th e r o r o e e s of h th c ch ; umm ts a ches, the f ld d dge t e a e ei i e o th e a s o th e o e . l mella , b ng d r cted t wards ngle f rmed by sp k s me a r a e n In No . 35 the la ll r a r ng me t is n ot s o we ll sh own ; here th e

a o i of o - i r i o e s st r c ns sts a r sette l ke a rangement, hav ng ten lance lat petal th e re are al so indicatio ns of lin es of cleavage near the ce n tre on th e

- right hand Side . In No . 33 th ere are faint indications of a radial

s i io in No . e or e i i con tr at n , and 34 ther are ten leven l ghter l nes all e i o s i e o e to i n a v rg ng t ward the centre , wh l , cl s the c rcumfere ce , sm ll

- a lie e i e o re wedge sh ped dark masses betwe n these l n s . The ther p i f r r paration s o nly faintly d sclose any appe aranc e o st uctu e . 2 e e o e i o f th e e a of o e io On p . 7 the gr at r c nv x ty c ntr l part the p st r r

s u of th e as e in i io io e r t o . rface lens , s en mer d nal sect n , was r fe red Th e same appearance can be mad e ou t ste re osc opically in the view of i in 1 th e i i en e its o io Nos . p ster r surface , as d splayed 33, 34 and 4 nc d c of the lighting in each case reveals the fact that th e central portio n of th e lens rises with a m ore pron o unced d egree of c o nvexity from the flatter and le ss co nvex p e riph eral p ortio n . The circumference of the l ens in m ost cases displays th at irregularity of o utline to which attentio n h as i o r o f zon ule o inn been already d rected (p . Heret the fib es the f Z in Nos an d 0 o of is t o are . attached , but 39 4 the equat r the lens seen o o to e o two o c rresp nd a flatten d z ne between b rders , as has been i o o s o o are already descr bed . In b th these ph tograph the d uble b rders ei i its o a o f e o o e a e seen , each rec v ng qu t fibr s fr m the z nul , the sp c between the two strata o f fibres c orresponding to the s o - called ca nal of P etit i i of i is o me i o f , the nner s de wh ch f r d by the c rcumference the lens i e th e two or e t o w i a e uatorial ly ng betw en b d rs , the surface h ch the n me q i o to i a n io n o zo h as . ne been appl ed An ther feature , wh ch tte t sh uld be a n No 1 i i is e i e is i i . d rect d , llustr ted 4 , where n a del cate membrane se n , h e re an d there raised from th e circumference of the lens by the tractio n of o i e t o on o e io o f the fibres the z nule . Th s app ars c firm the bs rvat ns o f e i o i of er ica sula r membra ne R tz us , and dem nstrates the ex stence a p p , to the dragging ou t of which by the fibres o f th e zo nule Retzius attributes the toothed and irregular o utline of th e circumference of the in o No 8 th e oe a i o o . cir lens . In the f t l eye at b rth , sh wn ph t graph 3 , o io cumferen ce of the lens is even an d regular . The p ster r surface

as if in e o - e i of appears puckered the centr by a f ur ray d cleft, the l mbs o rro i i which spread and branch irregularly int the su und ng t ssue . io o a o o of an Cur usly en ugh , the ppearance presented by the ph t graph

- 2 i i o io r a of th e eighth m o nth foetus (No . 4 ) exh b ts the p ster r su f ce lens l o and u i o i e o f co n fu l , r unded , str ctureless , and w th ut any ev d nce the i ion is in 8 i e i i in a e No . o d t d played 3 . P ss bly the appearanc exh b ted the l tt r SEEN FROM B EH IN D 47

- is due either to pos t m o rtem ch anges or to so me error in development .

In the eighth - m o nth eye the circumference of the lens is quite regular i a f e and w th out ny evidence of the attachment of th e fibres o the z o nul . F 0 or i o i 2 8 . s ee . further deta ls c ncern ng the lens pp 9, 3 and 5 ircu m l n t al s a e i a on an a e a e 1 The c e p c , wh ch me sures v r g mm .

in e is o e i iffe e n condition f i . br adth , seen fr m b h nd , under d r t s g l ght e e i i o of i a it a eafs as By r fl cted l ght , w th the f re part the eye nt ct , pp a i a i o i a io of ra s a d rk r ng ro und the l e ns . When v ewed by a c mb n t n t n mitted e i o i i i e re o it and reflect d l ght , the c rnea and r s hav ng be n m ved , s o u as a i a o e o i io s h ws p l ght nnular z n . Under the latter c nd t n the of on i ros it are e i a in s n fibres the z ule wh ch c s b tter d spl yed , s ce they ta d ou t as a an ai i o n i io e are d rk str ds ag nst a l ght gr u d . I n th s fash n th y i 1 i a i N s 0 . i a s n o . d spl yed 39, 4 and 4 Externally, the c rcumlent l space o offe a of corona radia ta for it b unded by the g red surf ce the , be remem bere d that th e rounde d e xtremities of the ciliary processes proj e ct somewhat in fro nt of the equatorial plane of the l e n s so that the wides t part of the interval b e tween the lens and the ciliary processes will lie i Th e i i i o f sl ghtly behind their anterior ro unded extremities . nner l m t e oi i wi o of Si the spac c nc des th the equat r the lens ; but nce , as we have i is n ot a i s o o or seen , th s lways a l near urface but ften a m re less o it is e r t o i e its i i o e flattened b rder, b tte descr b nner marg n as c rr ndin t e a r s o o u tor ia l zone of e s viz . a a o p g the q the l n , th t surf ce a und the circ u mferenc e which lies b e tween the attachment of the two strata o f of th e s us enso li ent the fibres p ry gam . zon ule of Z i nn or n li m n f s u s s r a e t o . The , the p e o y g the lens The i o i i o i fibres wh ch c nst tute th s structure , as seen fr m beh nd , are best i a i i in o . 0 s d splayed N 4 , where they appear as dark trands aga nst l ght o o i i i o i o of gr und ; the c rnea and r s hav ng been rem ved , a certa n am unt reflected light passes through the circu mlental space and thus re nders o an w i o it i io in m re apparent y structures h ch cr ss . In th s preparat n , i th e i o o of o i a wh ch v tre us has been rem ved , the fibres the z nule d spl y a a of i o in i i e the ppe rance be ng gr uped bundles, w th nterspaces betw en , in i e ar o i e wh ch the fibr s e n ot s o cl o sely packed t gether . Th s arrang men t is doubtless due t o the fact that the m aj ority of the fibres arise o th e coron a radiata in e cilia r r ocesses fr m the vall ys between the y p , where they may be seen springi ng fro m the b ottom and side s of thes e e in iffe ri t o oi o ut in rec sses d rent equato al planes . It may be well p nt this c onnexio n that some o f th e fib res arise n ot fro m the valleys but fro m the fore part of the orbiculus immediately behind the attachment n 6 an d ir of i ia o be in 05 . the c l ry pr cesses, as may see N 3 37 , where the co nnexio n with the o rbiculu s lies in line with th e positio n of the it i o o f r o . 0 in e o o e valleys . Fr m a study ph otog aph N 4 the st re sc p w ll i a i ar in th e of e io a in be ev dent , p rt cul ly upper part the pr parat n , th t, the i s are is o e in two s i a ma n , these fibre d p s d trata , wh ch are ttached 48 ANTERIOR HALF O F TH E EYE respectively to the two borders which include between them th e i z a o th e i ere of th e e l t is not dis equ a torial one r und c rcumf nce l ns . p uted that o th e r o f the fibres may be attached at interm ediat e points a o is o e o i of t o a th e l ng th z n , but the maj r ty the fibres appear h ve attach i i a Th e i l e e two o s o s ments nd c ted . nterva between th s strata c rre p nd to s o - ca nal o P etit i s o and in a the called f , wh ch urr unds the lens p rt o e o t o cir cumlenta l s ace o it ou a ear c rr sp nds the p , th ugh w ld pp that this inte rval has exten sio n s which pas s o utwards between th e fibres as s th e i ia o s th e ri they occupy the valley between C l ry pr ce ses . In ght i of i io in No 0 re of th e os io a o . h nd l wer s de th s reg n , 4 , the fib s p ter r s tratum have been torn away in rem oving the vitreous and its hyalo id e a o i i i a e o e io i e i e m mbr ne , thus pr v ng the nt m t c nn x n wh ch x sts b tween e e of e to o ior these lay rs . H ere the attachm nt thes fibres the p ster o r of e uator ial zone is o e b rde the q Clearly dem nstrated , as th y are turned o t owards the spectat r .

The fibres of the zo nule are clearly seen in the eighth - m o nth i a i no o o . 2 e i io f etal eye (N 4 ) th r rrangement requ res further descr pt n , except to p oint o ut that there are n o irregularities aro und th e circum e of th e s to i i e i to fer nce len nd cat the r attachment that structure . F or e i i i o o s ee . 2 further d ta ls c ncern ng the suspens ry l gament pp 9, n d 0 37 a 5 .

"it reou s . i i o i o i to its The L ttle need be sa d ab ut th s, as w ng trans e i i of its u o ut parent natur but sl ght ev dence str cture can be made . It is i n s itu in Nos a i o i of its i seen . 33 and 34 , where fa nt cl ud ness t ssue i i it e a i it to i nd cates s pr sence . In these prep rat o ns serves keep n o i io th e i o it its r h aloid mem p s t n structures wh ch surr und , and exte nal y bra e i r n s everywhe e applied to the in n er surfac e of the retina . In m os t o f o e r io s of i ie it e n in o or in the th r p eparat n th s ser s has be , wh le part , o e a o i io s r u r o f th e a oi rem v d ; under the l tter c nd t n , the st uct e hy l d an e i o of i o is s i i i to it is s e membr , w th s me the v tre us t ue st ll cl ng ng , en o i h e i s e Nos 6 s r a of i t e a e . verly ng r t n ( 35, 3 , 37 and the u f ce wh ch

is re o NO. h aloid membr a ne o i the by bscured . In 37 the y verl es the orbicu lus e its e is o a e i n it i i in , wh re presenc dem nstr t d by a tear , v s ble th e le ft - hand lowe r c o rner of the preparation th ro ugh th e tor n p o rtio n i i i e i the p gm e nted surface o f the o rb culus s m or clearly d splayed . I n the zo nular regio n its presence is indicated by th e filmy appearance e n in No 6 its i i a e o ion wi th e o e io repr se ted . 3 , and nt m t c nnex th p st r r

- es of o is i i in No . 0 i n o e r i fibr the z nule exh b ted 4 (r ght ha d l w s de) , e in a i to o it o e of e o wher , ttempt ng rem ve , s m these fibres hav been t rn o i i ia t away fr m the r c l ry at achment . 8 2 i is i in s itu in i o Nos . o In the f etal eyes , 3 and 4 , the v tre us st ll ne ther id ca is e i i io of i of h alo nal. No 2 ther any nd cat n the rema ns a y In . 4 a i i i o f e del cate smoky look nd c ates som e appearance structur .

For e i o e i s e . 0 6 1 furth r deta ls c nc rn ng the "itreous e pp 3 and . C HAPTER I" LEN S

S ies i u e a : n u er of e a a io n No 8 to T H I ser ncl d s mb pr p r t s ( s . 4 57) d e sign ed to e xhibit m ore Clearly th e c o n n e xion of th e len s with it s n s r li m e n s u s p e o y ga t . Th e sp e cim e ns in some in stanc es h ave been s u bject e d t o th e i n e o f in i a e s s o as to er o e o i o iffer flu nce sta ng re g nt , rend m r bv us the d en N 8 i o f th e a i tia i n of th e i o . s a o a o o a f t o t ssues . 4 ph t gr ph nter r surf ce o th e lens i i n th e a tella r ossa of vitreous r io w . e a a as , ly ng p f the The p p r t n ma e a e r th e i iar o h ad e r o e i i ro d , ft c l y b dy b en em v d , by sn pp ng th ugh the hyaloid membra n e at so m e distan c e fro m th e circumfe re nce of the e i of th e i r o was n a u u a a l ns ; the t ssue v t e us the c ref lly br shed w y, leaving the hyaloid membran e intact ; th e spe cimen was th e n stain ed in

- picro nigro sin . An insp e ctio n of the ph otograph in the s tereo scope o th e e n in in o of th e in e o i an th e sh ws l s ly g fr nt sta d hyal d membr e , an te rio r surfac e of which in th e u pp er p art o f th e ph o tograph exhibits a goffering arou nd th e p e riph eral cu t edge in c orre sp on de nce with th e cilia r rocesses i e a a a o its a e y p , wh ch hav been t ken w y fr m surf c . The o i o f e a as re i a e is n o t s o as to f ld ng the m mbr ne , he d spl y d , deep s ugges t th at it follows accu rately the c o ntours of th e su rface of the o ro na r r it i o n o n S i i o th e a s and c , but athe that d ps d w ly l ghtly nt v lley ri e a ro th e i e a we o e a i a a b dg s c ss nt rv l bet en the pr c sses , thus le v ng sp ce in fro nt between t h e fl oor of th e vall ey and the extern al s u rface of the ra n "uh t w i ar e . I i wa are o r ecesses o n e memb n th s y f rmed the f , h ch in c ommu n icatio n an teriorly with the poster ior ca mera of the aqueous cha mber d i i cilia la nds o f o i dis an o s ee . , nt wh ch ( p 44) the ry g C ll ns a i r r ar of rs r e io . s e e e e o ch rge the r s c et n The ec ss s , c u e , t aversed by o of th e e of th e u e in in ro of oi m em s me fibr s zo n l . Ly g f nt the hyal d bran e an d quite distinct from it are seen the fibres of th e s uspensory li a m t i n en . e are n o o re e in e o e io i g Th se l nger st tch d, s ce th r c n x ns w th th e i ia o e ee or wa bu t ei a to th e c l ry b dy hav b n t n a y, th r ttachment lens a e is ear own an d wi a i e r wi be i in s e n c psul cl ly sh , , th l ttl ca e , ll d st ctly e to be dispos e d in two m ore or less definite s trata wh e re they j oin the n o i i i i e ran e w i ie e i e o a o . le s , b th qu t d st nct fr m the hy l d m mb , h ch l s b h nd No is a r r ion in i o i io . 49 p oste io view of th e same preparat th s p s t n th e a oi e a e ie s in ro of e n s an d its i n e or o ior hy l d m mbr n l f nt the l , n r. p ster su rface is s e en to be irregu lar an d ragge d wh ere th e trabe cular exte n sio n s ro it in o th e e o f th e i reou s e e en or os f m t substanc v t hav b t n acr s . oi of a i r in e in is s i is it ar o A p nt p rt cula t rest , th pec men , that Cle ly dem n

1 234 I) 50 LENS strate s the existenc e o f the hyaloid membrane ove r th e su rface of th e

a a o a i as s e e n in o o a is a ear p tell r f ss , s nce , may be the ph t gr ph , there t i is i i is it o . in it acro ss s centre , thr ugh wh ch the lens clearly v s ble Th to re a oi ne d e tail will be furth er referred p sently . On the hy l d membra e of i i o e is an d if are i e th e impr ss the c l ary pr cess s seen , c fully nsp cted eo o e r o f o can in e o e e in the s ter sc p the fib es the z nule , plac s , be bs rv d n i is i o n through th e hyaloid membra e . Th s rendered d fficult by the am u t

a t o o io a of oi i n of loose tissue att ched the p ster r surf ce the hyal d , but the lower l eft - hand corn e r of the pho tograph the s uspensory fibres are i of th e e an clearly visibl e lying o n th e farther s de m mbr e . t h e s a a a io h as to u dis In No . 50 me prep r t n been subj ected a f rther Th o o ra i e th e a is a i w o f th e o i o ion . e sect ph t g ph , l k l st , v e p ster r surface of th e specimen ; but here o n e h alf o f the hyal oid membrane h as o as r n e h as o er ai th e of e n s been rem ved , and the memb a v l n back the l s io a h it h as b e e n stripped off fro m the p o ter r surf ce of t e c aps ul e . This co nvincin gly proves th at this l ayer is co ntinu ous over the surface of th e a a o a Si on th e Si it is i in a r o r p tell r f ss , nce left de st ll seen gre te part ve i a o o i i of eri a of th e ly ng the lens , and lth ugh the c nt nu ty the p pheral p rt membrane and th at which c overs the p osterior s urface of th e lens h as i r in a e a ea et if th e e o e i a e e been nte rupted pl c s by t r, y upp r t rn v rt c l dg of the m e mbrane be examin e d c are fully it can with c e rtain ty be trac e d r h on t o an d over the p os terior su face of t e lens . The c o nn exio n of this la r i th e o io of a s ai i i a e ye w th p ster r surface the c p ule must be f rly nt m t , as proved by th e m an n er in which it has b e en torn away fro m th e le n s o n ri i s i ar w i re i o n e i e i a s the ght s de , nce the p t h ch ma ns the l ft s d d spl y no or i e n e is e i to free ndep nde t dge , but apparently venly un ted the "u t t h e o a of th e i of h aloid po sterio r lens capsule . rem v l r ght half the y membra ne as i be n ot ar i wi it th e zon ula r bres for , w ll seen , has c r ed th fi , thes e are free an d indep e ndent of the hyaloid m embran e an d s till remain a to e e e o n t h e ri and o er Si i a r e att ched the l ns , wh r ght l w de the r r ang i ra a is u ment in t o tw o m o re o r le ss dist nct st t clearly seen . It th s appears t h at the fibres of the zo n ule must be regard e d as structu res i i a a o a oi n e o can n o d st nct and p rt fr m the hy l d membra , th ugh there be o th e e io e n e r i i e i d ubt that r lat n betwe them must be v y nt mate , spec ally i i a a i in th e a o f s w i at the r per pheral p rt , and p rt cularly c se the fibre h ch

N s . n 2 h n form the posterior s tratu m o f th e z o nule . I n o 5 1 a d5 t e lens a d lens capsule have been removed with the fibre s of the z o nu le still e n a e a in a e t o ri a off corona adh re t , c r h v g been t k n st p the l tter the No i n m o so if r is as a as o i . cilia far b ck p ss ble sta n has bee e pl yed , that a oi n e or ar s o f it are s i a to th e a a ion the hy l d membra , p t , t ll dherent prep r t , th e se owin g to their transpare ncy do n ot Sh ow ; but care was take n as r as os i e to r o a oi a i h as e e n s s fa p s bl em ve the hy l d , and th t th s b ucces ful is sugge ste d by the som ewhat fluffy appearanc e o f th e p osterior surface i of 2 . o of th e le n s as exhibited in the lowe r s pe cim e n in No . 5 The p nt LE NS S I in for i of w i io i o terest , the d splay h ch these preparat ns have been ntr

i for of a o 1 - cir duced is i . o , th s , that wh lst the space b ut 5 mm fr m the cu mference of th e lens t h e fibre s of th e zonule appear independent and e e are a e o w s e o co n s parate, yet wh n they tr ced furth r ut ard th y bec me u e so as t o o a i i e i o it s fl nt, f rm th n and del cate membran , wh ch , fr m i o i io a e o n a o s u rfac _o th e ars d sp s t n , must h v been t r way fr m the e fi p cilia r is retinae and i in its a io o ai n , wh ch rel t n theret must have l n betwee r oi i e a a r a that laye and the hyal d membrane nt rn lly . It thus ppea s th t u r e of o or sus ensor li ament o we m st egard the fibr s the z nule , p y g , as f rmed by the shredding o f a d e licate m e mbran e blended p o steriorly with th e layers of th e pa rs cilia r is r etin ae as it overlies the fo repart of the orbi

culus u o e ee cilia r rocesses . As S o and the f rr ws b tw n the yp has been h wn , res of th e o a i a o o o i i to th e these fib z nule , h v ng c mm n r g n , as they pass i e e of th e t o a e i o two s c rcumf renc lens tend rrange themselv s nt layer ,

' each attached re spectively to the anterior an d posterior bo rders of th e ua to i l zo f o o e r a ne o . i i e q the lens A few, d ubtless , ccupy an ntermed at o i io i i wee two o o to the p s t n , wh lst the nterval bet n the strata c rresp nds ana l o P et t c f i . The c omm o n o rigin of the fibres from the membran o us layers i is ow o in No in i ion i a descr bed sh n als . 53, and th s preparat the r sep io i o two a e as s is o ai o i n rat n nt l y rs , uggested , als f rly Clearly sh wn the eo ster scope . In th ose preparatio n s in which th e zo nule has been s eparated from its ri e a e a o th e o io o f its re wi pe ph ral ttachm nt , lth ugh c nnex n fib s th the Circumfe re nce of th e capsule of the le ns is clearly s een owin g to their n ow a e o i io the oi s of a a e t o a do no t rel x d c nd t n , p nt tt chm nt the c psule exhibit the same evidence of strain as when the parts are examined i n s it wi all u o io of o o . , th the c nnex ns the z nule c mplete nd h in Nos . 54 a 55 ave been intro duce d because these specimens o o a i iari h as n a a o its e a a e the c r n c l s bee sep r ted fr m scl r l ttachm nts , and in o u i o fixit o f o i io w i is i o a c nseq ence , hav ng l st that y p s t n h ch the r n rm l o n i io e s of th e o u as a r i i c d t n , the fibr z n le , reve led by t ansm tted l ght , c rossing th e circumlental Spac e are n o lo nge r represented in a tense an d o i io bu t a in a o w a oo e stretched c nd t n , appe r pl ces s me h t l s and e r laxed . N 6 h a t e i s a s e it e i i an a o . 5 as been dded o the s r e bec u xh b ts unusu l arra in a e o f th e on e In is r a a io as e a . ngem nt the ppear nc z ul th p ep r t n , s ee n on the right side an d also in th e lowe r left - hand c o rn er o f th e o o a are s o e i i a o n en i a a e ph t gr ph , there m del cate fibres hav ng c c tr c rr ng n d n . s a ea t o lie e we e n two s ra of on a co ment The e pp r b t the t ta the z ule , s n ca nal o etit ei a e is n ot a eque tly within or around the f P . Th r n tur cle r ; o ss i ma du e t o re e of a fin e e o e ia i i p bly they y be the p senc nd th l l l n ng,

a ia o r o e e to a a . p rt l c mpl t , th t sp ce 1 ’ N i of h e lens its ia e a o 67 - o s o . 57 s a view t with assoc t d p rts fr m a 2 m nth D 2 52 LEN S

foe . The i ore ear a oa e s eri a o tus lens , wh ch m n ly ppr ch s the ph c l f rm t an in a is ro n at it s u a or a o on i i o f h the dult, sur u ded eq t by c llar c s st ng th e coron a cilia r is inte rn ally an d th at part of the retina which u ltimate ly i o u fo rms the ora ser ra ta e xte rnally . The v tre s enclo sed in its hyaloid membra ne is s i in o i io i i s i i its a a is t ll p s t n , and exh b t w th n subst nce wh t th e a i in i e a io n iz h alo a of i e s v . id p rt cul r feature nt re t th s pr p rat , the y a rter a i o ar s t o th e o io r a of ere it ma y, p ss ng f rw d p ster r su f ce the lens , wh y be see n breakin g up into a n umb e r of bra n ch e s . F or fu rther de tails regarding the lens an d the z onule of Zinn see 2 an d pp 9. 37 47

54 POSTE RIOR HALF OF TH E EYE

the ve ssels and nerve s which here pie rce the scle ra so me of these are undoubtedly ve ssels and co rrespon d to th e poster ior cilia iy a rteries i i o r for s o i i a in er ich a wh ch , after pass ng f rwa d me l ttle d st nce the p or ioid l s ace e e a o f th e chor ioidal la er p , nt r the subst nce vascular y . Others o f a a i of i o e can o i i l rger s ze , wh ch ver tw nty be c unted , take a mer d onal o r o a cut of th e e io and are ei e i i c u se t w rds the edge s ct n , th r the c l ary e o r a i i i a i s i i nerv s themselves the p ths wh ch nd c te the r po t on . In e r of re a a io o r s o i to i a i o the upp part the p p r t n , c re p nd ng a l ne p ss ng n rth and o in o r of o is : it is n ot s uth the c mpass , an arte y s me length seen u nlike ly that this is one of the long poster ior cilia ry a rter ies which h as o o in f it r o i i a been t rn acr ss part o s c ourse th o ugh the perich r o dal sp ce . o o of o o a i to i of o is w At the b tt m the ph t graph , l ttle the r ght s uth , hat s e to be on f o i i i i th e ems e o the v rt cose ve ns p erc ng sclera . In the part o f io i is in ow i i e of o o the pre arat n wh ch shad (the r ght s d the ph t graph) , p . there are appearances in the distributio n of the pigment which suggest the arrangement of the radicles of the vorticose veins of the ch orioidal l aye r which lies immediately intern al to this expo sed surface of the s clera .

0 . Further details referring to the sclera may be fo und on pp . 7 and 4

Nos . 8 60 62 a i i e at th e e of In 5 , 59 , and , the next l yer, d v d d dge the io i t ch oi d s e i i e o is ori . ct n , mmed ately nt rnal the sclera , the In the a o i of i it is in o i m j r ty nstances represented as c ntact w th the sclera , i i a e a o i i of la mina usca the nterven ng l yer, as has b en st ted , c ns st ng the f l i na a hor i id i e t a m su r c o a l s. o and p These have a t ndency separate , as h as e e i n o a o i io o is o be n xpla ned ; u der n rm l c nd t ns , h wever, there nly an i e o i i i rregular lymph space betw en , thr ugh wh ch pass the c l ary nerves and the long posterio r ciliary arteries on th eir way t o the i i io i o i o io o io c l ary reg n anter orly . Acr ss th s space p ster rly the p ster r i ia a ie a e a o to th e o io i a i in th e C l ry rter s t k c urse enter ch r d l yer, wh lst io of a o a vorticose veins a o in reg n the equ t r the l rge , usu lly f ur number, a e it so as t o e o f e a o i tr vers enter the substanc the scl r , thr ugh wh ch they pass very obliquely in a backward dire ctio n . These veins are usually a in an r and o e air i oi s o f o rranged uppe l w r p , the r p nt emergence thr ugh ° the e in u 0 a scl ra be g abo t 9 ap rt . N 8 n d 62 o ioi e a a o o os . a o 5 , 59 sh w the ch r d s p r ted fr m the nerv us a of a rs o tica retinae i e on i r l yer the p p . The p gm nted appearance the nne fa of o ioi o is due as io sur ce the ch r d , thus exp sed , , has been p rev usly i to a e t o it o f i ment la er of th e expla ned (see p . the dh rence the p g y retin N 1 w f u of a a . 6 o o o I n o . 7 the h le the ter surface the uveal tr ct has be en expose d by the rem oval of the sclera and c o rnea from its o uter

rfa i f h e e is o er wi n on - a r su ce . Th s aspect o t structur c v ed th the v scula s u ra chorioidal membr a n e or as h as e s i p , f med , been lsewhere de cr bed , by th Th e e splitting of the tissue which unites it externally with the sclera . lin e of cleavage has taken place through the irregular lymph space POSTERIO R HALF OF TH E EY E 55 c a er ichor ioida l s ace i ie th e s a a lled the p p , wh ch l s between cler extern lly th e and the ch orioid internally . In this space thus laid o pen by re o of th e the s and n v i ra er o o e m val sclera, ve sels er es wh ch t v se the l s c o nnective tissu e within it on their way to the ciliary zo ne ante riorly are i e are h e cilia r n erves o f i i o r i can n ow s a e . s d pl y d The t y , wh ch e ght n ne be se e n passing forwards t o break u p anterio rly i nto brang hgs which I u nite to form the cilia ry plex us ( plex us g a ng lios us cilia r is) o n th e Ou ter e o a e of i ia e io n lie a to xp sed surf c the c l ry r g , where they extern l the orbicula r is cilia r is an d cilia r m uscle as ma e e i n a of y , y be s n the upper p rt h r i o a i on e o f er ar Si t e e o . pr pa at n Acc mp ny ng these n ves , ne the left de o f a o S e e s i s n i is o n e o f th e lon th e o o a e s . ph t gr ph , l ng l nder v s l ee Th s g poster ior cilia ry a rter ies pass ing forward s to the fo re part of the ciliary on to or i its ow o f o o i e Si o i z e f m w th fell the pp s t de , t gether w th the r of a io i i r i a i i a i i b anches the nter r c l ary a ter es , the rter al C rcle pl ced w th n th e a o f th e i ia a a n o f r i a e ia i is subst nce c l ry tt chme t the i is . Th s rt r l r ng n k own as the cir culus i r idis major . Th e o uter surface o f the u vea l tract exhibits a division into z ones in c o rrespo ndence with the differentiatio n in structure displaye d by its i u a f th e o o . s n io e in e o nner s rf ce Thu , a ter rly (se n the upp r part ph t is i o o o n i o o to an d is graph) there a l ghter c l ured z e , wh ch c rresp nds o r i i i i is f med by the o uter surface of the c l a ry muscle. Beh nd th s a o i o i i e os erio a i in i m re deeply t nted z ne , l m t d p t rly by l ghter r g w th e s i e i i f . a o o to o i io i o l s p gm nt Th s l tter c rresp nds the p s t n , w th n , the ora s er ra ta and in i o n of , the surface ly g between th s and the z e the ciliary muscle in fro nt overlies and harm onize s with the orbiculus cilia ris as o i e i i e i t o . i o o seen fr m the nn r s de At the l ght r r ng, c rresp nd ng the a a e of o ra r a a a a of i tt chm nt the se r ta , the p rallel rr ngement the ve ns w i i i o vor i h ch dra n nt the t cose veins is well displayed . Behind the a ttachme n t of the ora serrata th at p ortio n of the o uter surface o f the r w i o i e ch r i id i i o o s e o e . uveal t act h ch c nst tut s the xp s d Internally, th s is r i h o t e a rs o tica r etina e. e o o r i it ve la n by p p Ext rnally, the c l u wh ch e i i is a t o e n e i a t o it of i xh b ts l rgely due the pres c , ntern l , the p gment layer of th e retina ; but h e re th e c o nverging radicles of the vorticose veins are well displaye d as light tracts directed toward s a centre fro m i o ne of o i o e i a i — a i r e i wh ch the v rt c s ve ns r ses large vessel wh ch , t av rs ng th e o ioi a ou o f o suprach r d l space , escapes thr gh the capsule the gl be by i r i era o i p e c ng the scl bl qu ely in th e manner already des crib ed . The of o rioi o u i ar e e of w i e layer the ch d cc p ed by the l g r vess ls , h ch thes e in are th e o u r ia in i ie o i es it s vascula r v s m re s pe fic l th s v w, c nst tut la mina and as e o s u r a , thus xp e d is m erely cover e d by th e lamina s p chor i ida i o l s . i i th e as a a er an d ra in it ro th e i W th n v cul r l y , sepa t g f m p g e e o f th e re ina is th e chor io ca illa r la er of w i n o m nt lay r t , p y y , h ch dis i i e is i i e i h t nct ev d nce v s bl n t e ph otograph .

No . 6 e i i a ie o f the in n a o f u veal tract 7 xh b ts v w er surf ce the , except 5 6 POSTERIO R HALF OF TH E EYE

iris i ee n o e ro u ou ar its e ntire e e the , wh ch has b rem v d . Th gh t ne ly , xt nt it i o a i e w i s c ove re d by the pigm e nt l ayer of th e retina . Al ng l n h ch o e o a ser ra ta o f th e a rs o tica r etinae c rr sp nds t o the p os itio n o f the or p p , and a o for o e i in o n o f it o e o in t o th e s r a e ls s m d stance fr t , c rr sp nd g u f c

o f th e orbiculus cilia r is is i a h as in ar i e off , th p gment l yer been p t str pp d , s uggesting a mo re intim ate c on nexio n in this regio n be twe en t h e con

stit u en t laye rs of th e retina th an appears t o h old goo d else where . e io a o in th e o o a cilia i rocesses are een Ant r rly ( b ve ph t gr ph) , the y p s , r in th i o io n wi n u a o e cor ona cilia r is . ro f m g In f nt , the r c nnex th the an l r i a e is i a e o th e a e r o e er th e i i h as l g m nt d spl y d ; fr m l tt , h w v , r s been a e Th h s e io n in is io e ea th e det ch d . e c u t e dge of t e ct th reg n r v ls fo rm of the ciliary b o dy h e re du e t o th e Sh ape and thick n e ss of th e i iar u in oro n a orbicula r zone is s ee i i C l y m scle . Beh d the c the n , l m ted p o ste riorly by a som ewh at lighte r n arrow zo n e which c orrespo nds to o i ion o f or s r ra ta e e th e i m a e the p s t the a e . In the places wh r p g ent l y r of th e r in a e e s i e off ro th e o i u th e a an et has b n tr pp d f m rb c lus , rr gement of th e a e in w i are e e i ro th e i ia o e to sm ll v s , h ch h r pass ng f m c l ry pr c sses th i re e lie e r ari o f th e vena e vorticosae is w o . t but es , ell sh wn Whe th se in t h e s am e m e ridian with the main trunks of th e ve n ae vo rticosae th e e e a a ar a in a a i bu t wi e of is v ss ls ppe r r nged p r llel l nes , d th me ridian they pas s with varying d egre es of obliquity t o j oin th e area r i i i of d a ned by t h e trib u taries of the vo rtic o se veins . Beh nd the l ne a a e n o f th e ora e r a a th e ar of a a i con tt chm t s r t , p t the uve l tr ct wh ch s tit utes chor ioid i s i a it is ere o ai ow th e the d spl yed ; h verl n , h ever, by i e n a er o f th e r i ae th e n r ou a i a of i h as en p gm t l y et n , e v s l m n wh ch be

r o i i r flo ular - oo i e e m ve d . Th s p gm e nted stratum appe a s as a c l k ng lay r of ar in i an d i e i du e n o ou t o th e ir i of v y g th ckness nt ns ty, d bt regular ty its re moval or to the treatm e nt t o which th e specim e n h as be e n su b e en i e an d a e chor io s qu tly subjected . The fact th at th s lay r the subj c nt ca illa r a o e ie va scu la r la min a of th e orioi in w i p y l yer v rl the ch d , h ch the i a i e of th e e ae o i o sae are is o a o s for th e o re tr but r s v n v rt c d p sed , cc unt m o u re is a of e e e in is iew as o a wi a bsc d pl y th se v ss ls th v , c mp red th th t S o in a a a io n N h wn the l st prep r t ( o . In two o r e e a i a h as e o ou thr pl ces the p gment l yer be n t rn thr gh , and in on e of th e h oles s o produced (see the le ft - hand lowe r Side of th e o o r i i ph t g aph) the much lighte r clear stru cture o f the cho rio d s reve ale d . Th e ai n e iew of th e i a i o f o n e o f o i o e i e n f t r v tr but r es the v rt c s ve ns , s e ro o e in e a o re re to e i i th e th ugh the v rly g lay rs b ve fer d , xh b ts same ar e n i a in No 6 . rang me t as that d spl yed . 5 F o r furth e r re fe re nce t o th e details o f the uveal tract and th e pig a f e e o e i se e 1 0 2 1 . m nt l y r the r t na pp . , 5, 4

Nos . 8 60 62 an d 6 th e fu n du s o uli h as ee o In 5 , 59, , 3 c b n exp sed by r o a f th io r e a o f th e o e o f th e e e . o a the em v l o anter h lf gl b y Unf rtun tely, th e o ie a io of th e e i e in o o n ot r nt t n sp c mens , wh n be g ph t graphed , has POSTERIO R HALF OF TH E EYE 57

e u t o r e in th e or a i in o i ion no r o be n s ch as epresent th m n m l l v g p s t , c uld this defe ct be rem edied by rotatin g the prints s o as t o display the parts in ei a o i a osi io n s i e su o i e e i e i th r ppr x m te p t , nc ch w uld nterf r w th th r in h e e ri io i of e s e o o i ffe . o e t t re sc p c e ct I n c nsequenc , d sc pt ns g ven th m ,

" th e points of th e compass - are taken as a m ean s of in terpretin g the w s ea t o d et er h ori o a a . n o n a t oo it is n ot a z nt l pl ne U f rtu tely , , l ay sy i e th e i to h o s i e se a i o m n s de which t e eye b e l ng . W th thes re rv t ns the 8 i No . de s c ription of th e spe cimen s may n ow be pro ceede d w th . 5 exhibits the app earan ce of th e fundu s o f an eye which was remove d s o e i i f i e i en was c u t an d m t me after re c e pt o an njury . The sp c m o o a i in w i u e of th e era io n o in ph t gr phed w th t en ty m n t s Op t n , harden g or i e ei o Th e a a an is a o fix ng ag nts b ng emp l yed . ppe r ces d pl yed , th ugh re i s o o i u i i are as ea an a ro i a io t o co n the s me pt c ne r t s , n r pp x m t n the dition s in th e i n Th e in a i e e can re a be e . l v g y as aso n bly exp cted ret , o i a i to o e e os its a s h as th ugh d mmed and h v ng s m xtent l t tr n parency , n ot yet acquire d the s e m iop aqu e tran s lu c e nt l oo k which is s o charac t eristic of ar n e re a a io s Nor h as it o e i e a in its h de d p p r t n . bec m rr gul r i osi io a o i ion i is as so ia e i a ea an e of d sp t n , c nd t wh ch c t d w th the pp r c oe e a o - oo in o a io w i are s o o a met d m t us l k g f lds and elev t ns , h ch c nst ntly i in th e o i a u a i s In is a io th e w th rd n ry mus e m prepar t o n . th prep rat n pa rs optica retinae appears eve n ly spread ove r the in n er surface of th e o e e th e e o f th e e io w re a rea a e a a io gl b , xcept at dge s ct n , he l dy s p r t n of the n e rvou s fro m th e pigm en ted laye r t e n d s t o make its appear

ance . Within the cup fo rm e d by the post erio r h alf o f the glo b e two o ma r a i o n i s e a a e a i an e o sp ts y be e d ly rec g zed , p r t d by d st c fr m

e re to e of a o i in th e o r a . . o n e o o c nt centr b ut 4 mm , the l ght c l ur, the d rk or e is th e o tic dis h or a illa a e ellow s ot o r The f m r p p p , the l tt r the y p ma cula lu tea oin . In the ph otograph a line c onnecting th e two p ts o re o s t o th e i i a th e o o f th e s . To c r sp nd d rect n c ompa s SE . by E pl ce a a io o i a in its o r o i ion is i o p rep r t n appr x m tely c r ect p s t , th l ne sh uld be ro a n i it oin S i o o f e is to s a i it n ea t ted u t l p ts l ghtly s uth ast, that y unt l rly i o ori on a a A i i is i a falls nt the h z t l pl n e . S s o o rient e d the opt c d sk s tu ted

. t o e ia or a i of th e w i a e i 4 mm the m d l nas l s de macula , h lst the l tt r, wh ch i in th e i u i of th e o is a s i l es pretty nearly v s al ax s gl be , pl ced very l ghtly e o its ori o a b l w h z nt l meridian . Th e o ti c i m a lla a e as e n a r a a e a o m . p p p , pl c d , has b e l e dy st t d , b ut 4 to a s i e of th e a i o f th e o e i a a i - i e a ea a e the nas l d x s gl b , d spl ys d sk l k pp r nc wi a era ia e f a - m Th e i e o o u o f th e th an v ge d m ter o b out 1 5 m . wh t c l r disk is du e t o th e fact th at th e transpare nt retin al fib re s reveal th e w i e i s e or in t h e la mina cr ibrosa w i u s i e a ie th e h t t s u f m g , h ch pl g l k s ve ora men o ticum s clera e and e on w i th e n s sin f p , b y d h ch erve fibre pas g ro it is e o m e i a . 8 th e n re o f th ugh b c me y l n ted In No . 5 ce t the d k a e r as a ar i e o aro u i er is a s i a e r pp a s cle wh t sp t , nd wh ch th e l ghtly d rk on e w i a to S o e n h n i in a z , h ch ppears l p o utwards i to t e s urro u d ng ret l 58 POSTERIO R HALF O F TH E EYE

i u . i e o colliculus n ervi o tici is t ss e Th s elevat d surface f rms the p , and du e t o the increas ed thickness produced by the co nverge nce of the retinal optic fibres as they enter the anterior ope ning o f the fora men o ticu m s clerae th e i of i is o e i a p , c rcumference wh ch s m t mes m rked by a pigmente d ring which co rrespo nds to the abrupt cessatio n of the i e r of i a i is i i e in a io p gm nted laye the ret n . Th s d st nctly se n prepar t n i of a ri i n No . . No 8 s a a i o 59 In . 5 , there an ppear nce fa nt p le st at radiating fro m the optic disk into the su rro u nding retina ; this may p ossibly be due to the refl e ctio n of light from fibres of the optic n e rve N a or in i i of o o i . ot l yer, th s case may be ev dence path l g cal change unfrequently there is a Shallow h ollow within th e disk ; this is the h i l a u 60 e th e s o o ic l c r e a t is in No . o xc va ion . p y g p It well seen , wh re e levated rounded margin of the colliculus is seen to throw a deep

s h ad ow acro ss the n asal h alf of this c en trally placed depressio n . In i iew o f it t he e a a io a to a o e on th s v , xc v t n ppears h ve a m r abrupt wall its n a i o n its o in i Si a io it as l s de than temp ral aspect , wh ch tu t n seems to S o u o f t h e o i i l pe m ore grad ally t o wards the edge c ll culus . A d mpled a e n 6 i i in th e a i s o i . 1 s ppear nce of the optic papilla s al s en No . It w th n i n disk that the retin al vessels enter an d leave the globe . I the r ge e ral i i u io o ou th e e i i o a th e i d str b t n thr ugh t r t na the ve ns acc mp ny arter es ,

a o in th e r - fibre a os to the l rger branches pass f rwards ne ve l yer, cl e the la mina limita ns in terna s o in of r in a r o , that the surface the et he e exp sed e i can u u i in th y occupy a superficial p ositio n . The ve ns s ally be d st guish e d fro m th e arterie s by their greater diameter an d th e ir less o o o e t rtu us c urs . o i i i a i io are wi i i io of Th ugh nd v dual v r at ns met th , the d str but n the e t r ia e en n 60 an 2 is o mo i a . a r e v ss ls se i Nos . d 6 pr bably the st typ c l The centrali s r etinae as it i i i o i n i i at o r e o , l es w th n the pt c erve , d v des b f re its em e rge nc e th ro ugh the anterior Opening of the foramen opticum ra o ns it ie i i a a of o i is it scle e , c equently, when l s w th n the re the pt c d k , u ar as two or o f e e an r an d ow us ally appe s three branches , th s uppe l er b ranch usu ally turn over the rounded edge of the colliculus t o supply the uppe r and lower segments of the re tina ; each prim ary branch divid e s into a medial an d lateral branch; which are distributed respe c t ively to the nasal an d tempo ral areas of th e upper and lower retinal s e N an as o th e gments . ot unusually a m e dial h orizo ntal br ch p ses ver in r li of io o i a a io in i i a o ne p the phys l g c l exc vat n , l ne w th but aw y fr m o i io o f o a th e e io of m a cula the p s t n the m acula lutea . T w rd r g n the two o r a e i o e an d o e i ar sec nda y br nch s , der ved fr m the upp r l w r pr m y ra e o s o t o e o e i i a e i i th e b nches , curv utward s as ncl se an ll pt c l ar a w th n e re of i h i w i ma be e a as t e a u is . c nt wh ch m c la placed Th s , h ch y r g rded th e i i n N s 60 62 and is a arra is n o . typ c l ngement , well represe ted and , f s n o o n 8 an d . e o n ot s o ear i os . ee als , th ugh Cl ly, N 5 59 The mergence s s o th e i i o th e li of th e sio o i the ves el thr ugh t ssue , wh ch f rms p phy l g cal . POSTE RIO R H ALF OF TH E EYE 59

c u is o e a u e on i o s as is t o p , ften r presented by an br pt b nd the r c ur e , 6 s in th e o e e s o e i in No . 1 me xtent d splayed , but better een f etal y 6 i i e a o o in o e n n ot No . 3. The ve ns wh ch tak c rresp nd g c urs eed be further described ; they unite t o form a trunk which accompanies the

“ f i e arteria centralis retinae within the substance o the opt c nerv . Th e m a cu la or e low s ot in a n earl e x a tl , y l p , ly g , as has been st ted , y c y in o i io f h io o e of i a a i of e e is the p s t n o t e poster r p l the v su l x s the y ,

- - s in i o a a ro 1 6 to 2 0 . in o . 6 1 een N as a sl ghtly elevated v l are , f m mm i is i o . i in o o . o d ameter . Th s appears the ph t graph N N W fr m the pt c d k

two o of o lie n in o i o . The sh uld , c urse , early the same h r z ntal plane The s o a o f is in i a io n o o w llen ppearance the macula , th s prep rat n , d ubt a po st - m o rtem change emphasized by the harde nin g reage n t e mployed ; but it exhibits very clearly the depressio n in the centre of th e macular a a a ovea cen tr alis th e i e o f i are o re c lled the f , s d s wh ch f rmed by the rapid reductio n in the thickness o f the c onstituent layers of th e nervo us a of a rs o ti ca reti na a o ou i a e t o th e str tum the p p e. The d rk c l r mp rt d o ea i es its i i in r of S o f v , wh ch reach greatest ntens ty the cent e that p t , is du e to the re tinal pigment layer Shining through the rapidly thinning a o f u r i n 8 o of o I No . o l yers the nerv s et na . 5 , the ph t graph the fresh n ar e e o n a o o o n i t o th e o a is u h dened y , ly the d rk sp t c rresp d ng f ve i e e is n o i e of o i a a e d splayed ; th r ev denc the surr und ng m cular r a , due probably to the failure of the ph otographic plate e mpl oyed to repro duce iff e in r s e in o the d erenc c olou by which that area is d e fined . As e n b th

a a io o h as a iam of o 0 . these prep r t ns, the f vea d eter ab ut 5 mm

No . 60 in i u th e o i i a to lie In , wh ch the mac la and pt c d sk h ppen or i n o i o n o is ai m e nearly the h r z ntal pla e , the f vea ag n represented as a dark sp ot surrou nded by a light area displaying a s o mewhat puckered appearance ; beyo nd this a darker zone again intervenes between a i i a a e e i i o l ghter C rcul r r a plac d extern ally . This latter exh b ts a s me w a wo oo o it r a s to o a Si e of th e h t s llen l k , and fr m the e p sse , the temp r l d o i i e o o n th e e of w i t wo e ma pt c d sk , an levated f ld al g dges h ch v ssels y

. are e i in ai i a a be seen These appearances d scr bed det l , s nce they ppe r t o present a tran s ition stage be tween the co nditio ns already de s cribed i n OS . 8 6 1 d n d an o i are i a e in Nos . 62 a N 5 and th se wh ch d spl y d 59 , 6 3. In th ese latte r preparatio ns th e fundu s of the eye is traversed by an a i re a o e e n in o th e o i is i e n a to elev ted r gul r f ld , xt d g fr m pt c d k nt r lly th e re io of the e w re it e o o a i g n macula ext rnally , he ncl ses the f ve , wh ch always remains as a disti nct pit ; from this it tails o utwards into th e o ra e n of r i a o n th e s r a of w i it is a temp l s gme t the et n , u f ce h ch gr dually os l t . With the sp e cimen o riented approxim ate ly in its n ormal po sition th e o ie ar in th i a e ori o an e . s a a o f ld l s ne ly h z ntal pl Th ppe r nce , l ng n ow lica centralis is o o of a o k n as the p , und ubtedly the pr duct p st mo a as ma o a i o o Nos. 8 rtem ch nge , y be seen by c mp r ng ph t graphs 5 and o e ro th e m e e th e o in th e s o i io 59, b th tak n f m sa e y , f rmer fre h c nd t n , 60 POSTERIO R HALF O F TH E EYE th e latte r after it h as been s u bjected t o th e influen ce . of a harden i ng reage nt ; but here th e fo ld is n ot repre sen ted in its Characteristic o n o o du e to a i i was n f rm , d ubt the f ct that suffic ent t me ot allowed to elapse b e fo re the specimen was pu t in to th e h arden ing fluid for th e

o - o an e t o r i i i e e p st m rtem ch g s exe c se the r nflu nc . o 62 o i i S S E in s e of o ri In N . the f ld wh ch l es , t ad h z ontally as it s ou is es e in w ma be e its i a r . h ld , repr ent d hat y t rmed typ c l fo m In n u m ero us pre paratio ns in my collectio n the s hape an d dispo sitio n of is o are so re ar a a i as ma o a i 62 o . th f ld m k bly l ke , y be seen by c mp r ng N wi N 6 i a of th e oe e e o . a one s o e t o th e o u io th th t f tal y 3, th t f rc d c ncl s n th at th e c o n figu ratio n of the fold is - due t o some stru ctural difference in t h e i a w i in it s e for ina arti u ret n h ch determ es shap , here the ret seems p c larly p ro ne t o acquire an o edematous c o nditio n du e t o th e imbibitio n of u i o i an e a io o f i o i i fl d . P ss bly xpl nat n th s c nd t o n is t o be fou nd by a o n i e a io o f th e a a s u o f i re io c s d r t n v scul r pply th s g n . The macu la is a n a ie i es e e io o bu d ntly suppl d w th v sels, but the c ntral r g n f th e fovea is d e scrib e d as devoid of them . May n ot the o edematous c o nditio n in du ce d by p o st - m o rtem ch anges dem o nstrate the n atu ral meth od o f n u tritio n o f this regio n by the transu datio n of lymph from the sur rounding ve sse ls In No 6 th e a of of a o a e e . 3 appear nce the fundus f et l y at full term i i i l - i io o f s exh b ted . Here the i l s tre tched c o nd t n the p ars optic a retin ae is a a o w - defin ed s o o a i o r pp rent . Numer us ell w llen f lds pass r d ally f rwa ds fro m the Optic disk ; the larger of the s e usu ally correspon d in po sitio n an d i io t o ei w i a no t i to ru n d rect n the larger v ns, h ch ppear nfrequently a o i s e Th e a n o o ro in a . a d a o l ng the r m t p m ent surf c s l rgest br dest f ld , owe r is o in o o a a o or bu t w i in h ve , d p sed the ph t gr ph lm st due n th , h ch o osi io of e e o be ir e o i o a iffe s the n rmal p t n the y w uld d ect d h r z nt lly, d r fro m the others in n ot b eing asso ciate d with any large vess els ; o nly a small twig can be t raced alo ng its right edge from th e regio n of th e i a e re e n i i n r i . a a e to d s k . Th s s the plica ce t al s Its rem rk bl s mbl c the c on figuratio n of the c orre spo ndin g fold in No . 62 h as b e en already

e e i i and o mm . o th e e e of th e ref rr d t o . At ts w dest part s me 4 fr m c ntr o i i it i i s a w - defin ed it in e a o i pt c d sk , exh b t ell p , de p sh d w , wh ch marks

ntr li Th e oo - e in is e a the positio n of t he fovea ce a s . bl d v ssels th pr p ra io n are i a th e ei e i i i i e o ries t well d spl yed , v ns b ng d st ngu sh d fr m the arte by th eir greate r Siz e as they p ass over the thick e ned lip of th e collicu lus to enter the physiological excavatio n of th e optic disk a pron o unce d n e e ia t o the e o f th e c u rvature o their c ourse is we ll se n . Imm d tely l ft i a n r i in th e i i i of th e o a e s to be an anasto pl c ce t al s , v c n ty f ve , there s em a es of on e of th e a e ein m os i ng l oop between two of th e br nch l rg r v s . h e i s Th e e e of th e o i u s 15 i T opt c di k is ill defined . dg c ll cul th ck and o e o it s n th e e are n on e r in r und d , thr ugh substa ce v ssels see c v g g c u th e e e of th e t o pass alon g the s ides o f th e physio logical p . At dg

PLATE 1

Horizon tal antero - posterio r s e ction th rough th e glob e of the eye of an a u iewe s rom th e fron s is th e o er a f of th e re ara ion d lt, v d lightly f t thi th h l p p t 2 repres ented i n Pl ate . Th e i ris is here divid e d to o ne s id e of th e contracted pupil th e remark

- f th e n eri r s ur a e of th e ens i W s ou 8 mm. able fl atten in g o a t o f c l s e ll een . Ab t 3 to th e l e ft of th e cent re o f th e optic papilla is a d ark s pot (m) in dic ating th e s ion th e ea en ra is w is ere a e on th e surfa e o f a sw en po it of fov c t l , hich h pl c d c oll

re na th e a en ra is a s - mor em a earan e w i affe s th e fold of ti , plic c t l , po t t pp c h ch ct i n ar u n th m u a u a reti n a in th e reg o o d e ac l l te .

b n d i a rn ea . u u s s erae orres n an us e n th e o u er Co S lc cl , c po di g to j t b h d t

- un n a ar mar n f r s clero corn eal j ctio . c Att ch e d cili y gi o i is ; this is seen to be fi n ely irregular owi n g to th e fibres of th e ligamen tum p ectin atum iridis a e w be s een th e a n n ear a w r wn th e an er r e e bov it, ill f i t li Sh do th o by t io dg of t h e s u us r u ar s orn eae w w be e er em n s ra e i n o er a lc ci c l i c , hich ill b tt d o t t d th pl tes . d us ou s i e th e an u us r s w i is ere s wn as a u e owin to th e "t t d g l i idi , h ch h ho c t g s tretchi n g of th e iris roun d th e c ontracte d pupil ; d also m arks th e p oint W ere th e an nu ar amen is i e w amen th e r s th e iar h l lig t d vid d , to hich lig t i i , cil y mus e an d th e res th e e n a e amen are at a e s ee cl , fib of p cti t lig t t ch d ( Fig . I , p . s Th r e Cili ary proces . f e iris st etch e d s traight acros s th e aqu eou s ch amb er n e a i n s s e men th e i ris is cu t t o n e e a r n r ot th t thi p ci o Sid of ve y co t acted pupil . en e e es re n a at o ra s erra h en s e n s r s ta n a t h e g Thick d dg of ti ta. L (l c y lli ) ; an er or flat s u r a e i s in n a w th eri r s ur a r i a t i f c co t ct ith e post o f ce of th e i i s . Pl ced i n th e s o - call ed cana l o f Petit b etween th e fib res which form th e zon u le o in n

n u a ar s . R e na es s e s th s ar s en r n th (zo l cili i ) j ti l v l e ve i n e e bette t ha e arte ri es . h l er t s era . Re n a ars m Th e a n ra o n h Scl o ic ( cl ) ti (p optica) . fove ce t li s t e s u r a e th e a entra s . n O a a a a n i w t th e f c of plic c li ptic p pill (p pill . optic ) i h s a e a at n e a i i a a a n . in ts en re 0 r phy iologic l xc v io ( xc v t o p pill e optici) c t . Cho ioid r min r o ea . a a r s a. r e a en ra s r n r S ubarach (ch ioid ) p L c ib o q A t ri c t li e ti ae .

- n o id s a e . s u ra ma ra s ea n e ara n mem ran e su rr un p c D t l h th, li d by ch oid b o d in th e o n er e w h as a ia- ma r s men g ptic v , hich p t al i n ve t t . PLATE 2

H orizo ntal antero - posterio r s ection of the gl obe of the eye o f adult ; e a of e e re resen te in te 1 oppos it h lf y p d Pl a .

Th e u i is mu on ra e an d th e an er or s ur a e th e en s is u i e p p l ch c t ct d , t i f c of l q t flat As wi be s een on om aris n h er o r is i n . ll c p o with t e oth phot g aphs th s a u n u sua a earan e but in n o er re ara n is th e u i so on ra e as l pp c , oth p p tio p p l c t ct d i n n Th e re n a a t h e mar n f h r rm a th at s ee h ere . ti t gi o t e o a s errata fo s double

- e e e ro a a os m r em an e . fold d dg , p b bly p t o t ch g

b n r r am r me ra u i i r er a orn ea e e a an er o . c C . A t io ch b (c oc l t ) Scl o

rn n i n . d n u u r e i iar or us are . co eal j u ct o A g l s i idi s . C l y body (c p cili ) f I ris s tretch e d right acros s th e a ueous Ch amber and cut to o ne s ide of a s ma u ens en s r s alln a an eri r s ur a e of ens remar a ll p pil . g L (l c y t i ) t o f c l k bly n i r Or i u i ar h ar ess es r ssus ar s . i u s s fl atte e d . Cil y p oc (p oce cili e ) b c l c li i i a r a a r n d r h ar ar r n a d spl ying a st i te d pp ea a ce an cove e d by t e p s cili is eti e . °

- 7 Ora s errata : alon g this edge th e reti n a form s a thick en e d fold . h R etin al

1 er er m n ars i re n a . n e . R e a a e O vess ls Scl otic (scl a) . ti (p Opt c ti ) ptic i a n i i a a i n in i n r a i n i i a a w e o ts e e e a er . p pilla (p p ll . opt ci) th xc v t c t ( xc v t o v optic ) i rio ea am n ri r n ra a er re n a o r a o a . e r Cho i o d (cho id ) . p L i c b s q C t l t y of ti

r - m r ea o f a e ri n r is r ina . r u ar n a s ur a a S ( t a ce t al et e) S b ach oid sp c e . D a t l h th i in in n i r n i Opt c n erve l ed ter ally w th a ach o d . PLATE 3

- Vert ical antero posterior section of l eft e ye .

Imme diate ly be hin d t h e poin t of entrance of th e optic nerve a wo rm - like

we n th e re in a is seen s is th e s o - a e a en ra s a os S lli g of t ; thi c ll d plic c t li , p t morte m chan ge due to t h e action of th e h arden i ng reagen t it co rrespon ds i n s n to th e ma u a u a s e i n s ows er we th e su us circu po itio c l l te . Thi s ct o h v y ll lc a d c i h ar o n lari s corn e e ( ) ut across . Th e section al s o div d es t e cili y body r in th e ur r s is ere a e ith e s id e f row between adj ac en t ciliary p oces s e . It h th t t h e res the amen o f th e en s are a a e ome of es e res can fib of lig t l tt ch d . S th fib

be ain s een on th e ri - an s i e th s n f tly ght h d d of e e ctio .

i rn a . n . b ri ir u r s e a or ea n e r C m r c ri . d u us a e C A t o ha be . I s S lc c c l co

e an a emm s nu e n o u s r e ar r us are . C l of Schl ( i s v s s cl e a ) . f Cili y body (co p cili )

ar r ess ro essus i ri h am n t en s fibrae nu ares . g Cili y p oc (p c c lia s) . Lig e of l ( zo l ) m es s e s 2 n s r sta n a . R n ra e e a le r . l er s e . L c y lli j ti . Cho i oid Scl otic ( cl ) V l

re na n a en ra orr n n th e ma u a u ea . of ti . Plic c t lis c es pon di g i n pos itio to c l l t

- o a a n . . N i u a o n e r e . ur ma ra e P pill optici p opt c s . q D a t l Sh th of ptic v

(vagi n a n . optici) . PLATE 4

er i a an r - s erior s ion o f e e V t c l te o po t ect y .

To th e ur er s e o f th e o i a a th e a en ra s mar in th e f th id pt c p pill plic c t li , k g si on f th f i I r th o e o ea en ra s s s een . n on e a ta m en t of th e i r s po ti v c t li , f t of t ch i th e e e of th e s u u s r u is orn ae can be s e e n i n Th dg lc ci c lar c e Sh adow (c) . e pupillary edge and anterior s urface of th e iris is well displayed ; a d ark s pot o n e r s ma i ff ithe ide rks t he p os tion of th e c an al of Schlemm (e) . Th e di eren ce e ween th e rt a an d en ra ar th e en s is ear n Th e res b t co ic l c t l p t of l cl ly s how . fib of th e amen h n n lig t of t e le ns can be s ee but fai tly (i) .

r b i a r a n n er m r am a u an ri r . u us Co ea. A t or ch be (c e oc li te o ) c S lc

r u ar s rn eae d r s . e an a emm s nus en s us s erae . ci c l i co . I i C l of Schl ( i v o cl )

s e r r a r ri r ar us i are . f Po t io ch mbe (came ra o cu li p os te o ) . g Cili y body (corp c li ) h ar r s r u i iar am n fi r nu ar es es s s i e en s b ae es . Cili y p oc (p oc c l is) . Lig t of l ( zo l )

R n a . h ri i l er s e ra . m es se s j eti Cho oid (chor oid ea) . Scl otic ( cl ) V l of

reti n a . n Plic a cen tralis : correspondin g to pos itio n of m ac u la lutea an d fovea

- i o . n a a a i a n . ur a r a f ce tra l s . Optic p pill (p p ll optici) p D mat al s h e th o optic

i . ic r r r r ina . n e a na n . e a n r s e erv (v g Optici) q t n e rve . A t i ce t ali t e

PLATE : 6

- - ame Antero posterior s ection th rough th e eye of a man aged thi rty n in e . S s e men as p ci Pl ate 5 . Th e len s with its capsu le and th e vitreou s have been remove d immediately i n fro nt of th e attach ed margin of th e i ris th e S had ow c ast by th e sulcus r u aris r Th i i r ro s are we is a e and ci c l co n eae can be s een . e c l a y p ces es ll d pl y d

th e or i u us i aris i n . Th r i i in r a ar e a e b c l c li s well s h ow e et na s g e t p t d t ch d, but alon g th e li ne of th e o ra s errata it i s seen t o be more fi rmly fixed to the s u a en s bj c t tru cture s ; posteriorly the optic cup is clearly s hown.

a rn ea b n ri am r am r i ri r r s : immedi . an c Co A te or ch b e (c e a ocul te o ) . I i ately in fron t of its attach e d circumference evid en c e of th e s u lcus circu l aris orn ea m b en d ar r u i r e e ar ro ess e a s a . c y e s e . Cili y body (co p cil ) Cili y p c

r s ar r . Or (p oc es us ciliaris) . f O rbicu lus cili is with meridion al fib es g a s rra a h n e i r e . R . e t etina (pars optica reti a ) Chorioid (chorioid ea) . j Scl otic

s era . h R a 1 O c u a n t a a an e a . ( cl ) e i n l ves s els . ptic p pill d optic p ( xc v tio

- m . n . Optici) . Optic n erve n D ura matral s h eath of optic n e rve (vagi na

. o rt r n r n e optici ) A e i a c e tralis eti a . PLATE 7

Anterior h alf of an antero - posterio r s ection o f th e eye vi ewed obliquely from b ehin d . Th e ora s errata is well se en ; along this goffere d e dge th e retina is s een to th e u ri an is s ri r to be mo re firmly attache d s bj acen t cho oid th it po te o ly. Th e radi al arrangement of th e o rbicu l us ciliaris is clearly Shown on th e left of Th men os e r fa f th i r s ars uv li t h e specimen . e pig te d p t rio sur ce o e i (p ea s ri is is is a e rm n th e an er r wa th e s er or am er ame ra i d ) d pl y d, fo i g t io ll of po t i ch b (c eri r In is o ra th e h as ai e a th e res oculi post o ) . th ph tog ph light f l d to c tch fib of i men of th e n s o a e are n o e i n th s im n th e a e s t re ea e e e . l g t l , th t th y v l d p c

rn . b ri r am r am i n ri r c u ar a Co ea Ante o ch be (c era ocu l a te o ) . P pill y margi n of iris . d Posterior chambe r (camera oculi poste rior) with th e o s erior i men e s ur a e th e r s i n r n and th e un an eri r p t p g t d f c of i i f o t, bl t t o extremities of th e Ciliary proces ses p roj ectin g into it posteriorly ; th e zonu l e

f n n is n t r s n . e iar r u a i a o Zi o h e e ee Cil y body (co p s cili re) . f C li ry s es r s u n r i a h O r i u s e s n s a n . p roces (p oce s s ciliares) . g L (le s c y t ll ) b c lu

iar s o er ai n i r r i ra R . O s erra a . in cil i v l by th e pars cil a is etinae . t j et a i l k r o rio a . r s ra Cho id (cho id e ) Scle otic ( cl e ) . PLATE 8

n ero- os erior s e i n r u th e ore ar of th e o e th e A t p t ct o th o gh f p t gl b of e ye .

is se ion s ows er we th e sus en sor amen of th e en s ar i u ar Th ct h v y ll p y lig t l , p t c l ly

o n th e ef s i e . As wi be seen th e res of th e on u e inn onu a l t d ll , fib z l of Z (z l iaris s rin rom th e i iar o an d th e r u u ri cil ) p g f c l y b dy o bic l s cilia s (see PI. 37) e s e ara e as e ass to th e en s s ome oi n to th e fron ers th e th y p t th y p l , g g t , oth to posterior surface o f th at structure ; b etween th e diverging fibres and th e ir umferen e th e ens is a s a e s own in s e on th e an a of e i c c c of l p c h cti g , c l P t t ri Th e s e on a s is a th i h o r th e Spatia zonu la a. cti l o d pl ys e re l at on ship of t e su us s erae c at the un ion e ern a of th e rn ea an d s ero to th e lc cl ( ) , j ct xt lly co cl tic , su lcus ci rcu l aris corn eae (e) Situ ate d at th e ang ul u s i ridis .

m n u u r r am e r a era u a er r . c s s era n b n e e . a C or ea . A t io ch b (c oc li t io ) S lc cl d r e u u s r u aris rn eae . ster r am er un e e in I i s . S lc ci c l co f Po io ch b bo d d b h d n d th e i amen th e en s Th e an a e by th e cili ary p roc es ses a l g t of l . g c l of P tit r th e n u ar res fibrae on u ares i n fr n an d e n (Spatia zonula ia) with zo l fib ( z l ) o t b hi d . i ar r r i r i es s es su s ar s . n h Ciliary body (corp us cilia e) . C li y p oc (p oc cili ) j L e s l i . r r . O u ar O a e rata m na n r . a n k r i u s s R e . o cryst lli a . b c l s cili ti Cho i id o ra or us t re um . Scle . p C p vi PLATE 9

n ero - os eri r se i n rou an e e in w i owin to th e resu an A t p t o ct o th gh y h ch, g lt of i n ur th e an t erior sur a e of th e iris h as e me ose a eren th e j y, f c b co cl ly dh t to n urfa e th rn i tern al s c of e co ea. Th e p osterior ch amber h as th us b ecome en ormously en larged at th e " e ense of the an er r am er w i h as i n on s e uen e een om e e xp t io ch b , h ch c q c b c pl t ly

era e . AS a res u a sor n a ura isse n h as en su e an d th e oblit t d lt t of t l d ctio d, s pe cimen h as been i nclud ed becau se it affords an admirable demonstration of

t h e two a ers h n i n i h e - e an a of e e w n l y of t e zo ule of Z n w th t so c all d c l P tit b t ee . A is e s n t n PIS 1 2 e s w ee ere and a so in s ome th e er se s . th ll h , l of o h ctio ( , , C r um eren e of th e en s is un an d u rn s e wi two e es t o th e an eri r i c f c l bl t f i h d th dg , t o of which th e fibres of th e susp en sory ligamen t can be s een pass in g t o be a a e to t h e a su e th e en s w s th e s erior S ee in n a tt ch d c p l of l , hil t po t h t, co t ct wi th e a oi mem rane is seen to en w th e a su e o f th e ens at it s th hy l d b , bl d ith c p l l s eri r po t o edge .

a n ure orn ea b G rea s en e s er r am er amera u I j d c . tly di t d d po t io ch b (c oc li os eri r th e u e a s u rfa e th e r s is e s e as th e I r s is s rea e r p t o ) ; v l c of i i xpo d, i p d ov th e n n r s ur a f t a n r r n s f th e i r r es s es I e f ce o h e corn ea . c Th e te io e d o c li a y p oc u e rwar s th e s ru ura th ris d ar r us p ll d fo d by t ct l fold s of e i . Cili y body (co p

are . e n er r res nu e o f n n rm n th e s u s en s r amen cili ) A t io fib of zo l Zi , fo i g p o y lig t th e ens e ri r a e n u e n n e wee n the two i s th e of l . f Pos t o l y r of zo l of Zi ; b t s o - a e ana n n r n n e i u n r u m c ll d c l of Petit . Le s (l e s c ystalli a) : ot ts bl t ci c

e re n h . n a e . i s c r h e Or u us ar s . i Ora rra a S clerot c le a R f c bic l cili i s e t . j ( ) ti ars a re n ae O n a i e a a i . (p optic ti ) . l ptic p p lla with xc v t o PLATE": 1 O

n ero - o s erior sec ion rou h e e A t p t t th gh t ey .

Th e u i is wi e i a e wi nse uen i en n of th e i r s w i p p l d ly d l t d, th co q t th ck i g i , h ch at its circumferen ce is n ow seen to occupy almost comp letely th e sulcus d Th e i reous is in s itu its e i a e m ran ci rcu l ari s corn eae ( ) . v t d l c t hyaloid me b e (membran a hyaloidea) is well displ ayed to th e right of th e en tranc e of the i fi ne on ne i ns wi t h e s urfa e of th e re n a n optic n erve ; ts c x o th c ti are al s o s ee .

a b n eri r am er amera o u i an r i i a rn e . e r c r s w Co A t o ch b (c c l t io ) . I , th ' wi e a e u . a u us r u ar s rn eae u u ie the d ly dil t d p pil S lc ci c l i co , f lly occ p d by i n ris e iar on ra e an d e e . o r us i iar r essu s c t ct d th ck d i Cil y b dy (co p c l e) . f P oc i in a n s of th e amen th e n s iar s . a n e . h s rr a cil i g F t dic tio lig t of l Ora e at . i R a Chorioid r oi ea . h er s era l i mem etin . j (cho i d ) Scl otic ( cl ) Hyalo d i n n i b ran e (membrana hyaloidea) : ts co ex o ns with th e ret In a are also vis ible . m Optic n erve . PLAT E

Antero - posterior s ection th rough th e eye (s ame eye as Plate

Th e re us h as een remo e wi th e a o mem ran e a ta i vit o b v d th hy l id b , g of wh ch is seen s i a a e th e r um eren e th e ens o n th e ef s i e Th e t ll tt ch d to ci c f c of l l t d . re na h as een a en awa an d t h e ir s h as also een rem e Th . s u us ti b t k y, i b ov d e lc ci rcu l aris corn ea is well s hown imme diately b elow th e su lc us on the left s id e ma be s een the s urfa e rom w th e ir s h as een rn awa rres on y c f hich i b to y, co p d m n r Th r a ing to th e ann ular ligamen t (liga e tum ann ula e) . e el tion of the s ulcu s r u r s rn ae d to th e s u u s s erae c is a so is a e Th i ci c la i co e ( ) lc cl ( ) l d pl y d . e p g ment ed pars ciliaris reti n ae h as be en s tripp e d o ff from a co n s id erable surface of i i r n of th e ora e rr a th e orbicu lus ciliaris immed ately n f o t s at .

b n eri r am er amera u i an er r : rou h a Corn ea . A t o ch b (c oc l t io ) th gh t e removal of th e i ris th e anterior an d pos terior ch amb ers h ave been th rown

n n e c u us s erae at ou er su r a e s e r - orn ea un on i to o . S lc cl t f c of cl o c l j cti . d Su lc us circu lari s co rn eae : on th e l e ft- h an d s ide of th e s ection this is s een u is n r m th e s u r a e r m w th e r s h as en o rn q ite d ti ct f o f c f o hich i i b e t away .

e r or us are . ar r es ses r us i iar Cilia y body (c p cili ) f Cili y p oc (p oc es s c l es) . n s ns r t in a i n s itu h u r a e of r i u us ari s r m w g Le (le c ys all ) . S f c o b c l cili f o hich th e men e ars i iar s r e inae h as een s ri e o ff i r o pig t d p c l i t b t pp d . Cho i id i la i a i i n . ch or oIdea . ero s era . O a a a ( ) j Scl tic ( cl ) pt c p p ll (p p ll Optici) . PL ATE 1 2

An tero - p oste ri or section th rough th e eye (same preparation as Plates 1 0 and 1

T w its a su e and th e i reous a e een remo T h e l ens ith c p l v t h v b ved . h e rn awa r m its a a me n and th e re in a h as i ri s h as been to y f o tt ch t, t b een tak en m r awa ea in mu of its en a e a a e th e ori . on th e y, l v g ch pig t l y tt ch d to ch oid Al g li n e of th e o ra s errata th e pigmente d portion of th e p ars ciliari s retinae h as s ri e awa ou an er or remain b een compl ete ly t pp d y, th gh t i ly it s as it pass es r ses Th e re a i n forwards over th e ciliary p oc es . l t o of th e sulcus s cle rae (c) to t h e su cus r u ar s orn eae d is we s a e and th e a er is we seen l ci c l i c ( ) ll di pl y d, l tt ll immedi ately in fro nt o f the su rface from which th e i ris h as b een torn away

- r n n ear th e corn eo scleral ma gi .

i r m r m a rn ea b n er a e a era u i an eri r . c u us Co . A t o ch b (c oc l t o ) S lc s clerae

- d u us ir u ar - at corn eo scleral m argi n . S lc c c l i s corneae : o n th e l e ft h an d s ide of th e s e ction this is s een qu ite dis tin ct from th e surface from which th e i ris h . e ar or us are r as bee n d etach ed Cili y body (c p cili ) . f Cilia y processes r ur a e r u us ar s r m i (p roc es su s cilia es) . g S f c of o bic l cili i f o wh ch t h e pigmented

ar r r n ae h as een s r e . h ri ri i i p s cili a is eti b t ipp d Cho oid (cho o d ea) . Sclerotic

O a a n . i e t a a . (s cl ra) . j p ic p pill (p pill opt ci)

PLATE 1 4;

Th is view represents a quarter of the ocular glob e cut from pole to pole .

is me o o f s e on h as een a e s o as to en a e th e iris to be ,Th th d cti b dopt d bl n m The ens i its i amen and th e i re us pu lled back without a y d a age . l W th l g t v t o Th e ua ran the ir s h as een rawn a in o r er have be en removed . q d t of i b d b ck d to th r an us e s th e su us ir u ar s rn eae c op en up th e angl e of e i is d th xpo e lc c c l i co ( ) . Th e vertic al striae reveale d at th e b ottom of th e sulcus are due to th e arrange m th e res th e amen um ectin atum i ri s the in erva s e ween ent of fib of lig t p di , t l b t n t n a which commun icate with th e spaces of Fo a .

m m n i r c u us a r a b n er or a er a era u i a er o . Co ne . A t i ch b (c oc l t ) S lc r u ar s rn eae at th e m w i th e er a s s e res th e ci c l i co , botto of h ch v tic lly di p o d fib of ’ m tin m i an b a n s een a Th e p ectin ate ligamen t (ligamen tu p ec at u irid s) c e f i tly .

r s u a e ar or us are . ar r ess . i i p lle d b ck . Cili y body (c p cili ) f Cili y p oc O r u u ri h Ora s errata : ere th e e ema th e ars g bic l s cilia s . h o d of p

re in ae du e e er to os - mort em an es o r th e i n uen e th e reser a e t , ith p t ch g fl c of p v tiv , is very de fi n itely limi te d i n fron t i n h armony with th e attach e d e dge of th e

i id r a la er s era . R n Ch or o o o e . r rr i a . i o a se ata . eti (ch i id ) Scl otic ( cl ) - erior iew rou th e e f a fu - ime foe u s ive on da An tero post v th gh e y o ll t t (l d e y) .

No e th e a s u e an d ro orti n a e reater i n ess of th e cornea th e t b ol t p p o t ly g th ck , s a w an eri r am e r th e m re s eri a len s and th e sma er i iar h llo t o ch b , o ph c l , ll c l y

Th e re n a is er and r wn i n o o s . H ow mu of s is due body . ti thick th o t f ld ch thi t o os - mort em an e or th e us e reser a i es it is iffi u sa but p t ch g of p v t v d c lt to y, ‘ ’ p oss ibly th e occurren c e of th ese folds in th e livi n g accounts fo r t h e s h ot o r ‘ ’ watered Silk appearan ce of th e retin a reveal e d o n th e ophthalmos copic amin a ion of th e e es of oun i ren ere is a ta of issue m ex t y y g ch ld . Th g t ( ) exten di ng forward s from th e optic p apilla ; this is p robably a fold of retin a i h as een i i e n th e n ear a t h e s i n Th e o ra s erra a is wh ch b d v d d o h lf of ect o . t n o lie mu n earer th e i iar an i n th a u see t ch c l y body th e d lt .

a rn ea b nteri r am er amera u i an e r r c u i ar Co . A o ch b (c oc l t io ) . P p ll y r d n f S chle mm n us n sus s e ra e r n s . a a o ar ma gi of i i C l (Si ve o cl e) . Cili y body i i r r s r or us are . a esse essu s ares . Ora serra a (c p cili ) f C l y p oc (p oc cili ) g t , a e n earer th e ar o an in th e a u an d rm n w a a ears pl c d cili y b dy th d lt, fo i g h t pp to be a i re u i a e mar n h en s en s r s a n a mu m re th ck d pl c t d gi L (l c y t lli ) , ch o i s n h e a u i R a . er a a n t . e n r r e a h ra . ph ic l th d lt ti j Cho oid (cho ioid ) . Scl e l Th e run en t u i i m m r n m n s h k vi reo s w th hyalo d e b a e (me bra a hyaloid ea) . m T s u f su d r a a cut n . n a o e e re a a a n . . g ti , p ob bly to fold of ti P pill optici o O n r r r n r i a e m i r m l . e e a e a s re n ae . u nte va a e ptic v . p A t i c t li t q Sp ti g

r ura- matra ea of n e D l Sh th optic erv . PLATE 1 6

% n e ro- os er or se i n rou the e e a f e us a ou 6 mon s A t p t i ct o th gh y of o t b t th .

No e th e er i orn ea th e s eri a en s an d th e re un an and o e t v y th ck c , ph c l l , d d t f ld d re n a art u ar an er or on th e re ion w i u ma e e e s n o ti , p ic l ly t i ly g h ch lti t ly d v lop i t h o ra er a a t e s r t . Th e u ar mem rane e en n a ross th e an eri r am er is seen p pill y b , xt di g c t o ch b , i i n im ia e e in th e os erior s urfa e th e rn n s ect o med t ly b h d p t c of c o ea.

b r ri i a a r e i s e . c u n n a Scl erotic (s cl e a) . P cho o d l p c Re d da t fold of i ra erra a d n n in s n o s . ri i r reti a correspo d g to po it o of t Cho o d (ch o ioid ea) . ir u ar mem ran mem r n a ar r e r s . e a u i aris e Cili y bo d of i f P p ill y b ( b p p ll ) . i in a h en s en s r s a n a s er a e . orn ea : n o e its rea g L (l c y t lli ) , ph c l Sh p C t g t i u a d al oi m m r n r n ne . r s n i p ropo tio ate t hick ss Vit e o hy d e b a e . j Cil ary

i . h i r in a a r 1 i e . p roc ess (process us cili ar s) Th ck t l l ye Cho ri o d . PLATE 1 7

1 - s erior se ion rou th e e e of a oe us o f 6 m n s An tero po t ct th gh y f t ,7 o th .

is is th e same S e men as PI. 1 6 n ifferent e and iewe so Th p ci , o ly d ly light d v d as t o exhibit th e hyaloid artery run n in g forwards from th e back of th e vitreous

ch amber to th e po sterior sur face of th e l en s . '

b ris . c ar ro es r e us i i i a n s rn s o s ar s . e a Co ea . I Cili y p c (p c s c l L n n n i e e u a a er or mar n f r n . (len s crys tallin a) . R d d t t gi o eti a arS optica)

r i e ra . e ri ri i a s a e It a oi arter art eria f Scle ot c (s cl ) g P cho o d l p c . Hy l d y ( i ri i i i i a R t na. o o or r e o ea . la s o r . hyal o d e ) . i 7 Ch d (ch i d ) cl e t c (s cl e a) PLATE 1 8

% ’ Antero - posterio r section th ro ugh th e globe of the eye of a 6 - months us as Pls 1 6 an d foetus (s ame foet .

h en s wit the reous o e er wi ar of th e re in a ars i a T e l h vit , t g th th p t t (p opt c ) n d ar th e ars i i i ar th e o ra s erra a a ar s see PI. a e een n e t , p t of p c l ( h v b " No e the rea ro o rtion at e thickn ess of th e orn a th e u i ar r m e . e e ov d t g t p p c , p p ll y b an d t he an d re un an re n a ars a Th s a f m m ran e . e o e b ( ), thick d d t ti (p optic ) t lk r m a r ss e re it en r th i r th e hyalo id arte y t o c o b fo te s e v t eous .

a rn ea . b u ar mem ran e : its n n e n w t h e r s c is s e n Co P p ill y b co xio ith i i ( ) e . d R e n a n ear t h e o ra s errata th e e i t rn re s m c r s . e s e a s e I i ti ; dg o h , o of r m e e th i n i n h a e en e : s e e e me ra n PI. th e reti a s b ov d Sp c photog ph e d 5 7 .

e ar ro esse s r es sus ares . O r u us ar s r m w th e Cili y p c (p oc cili ) f bic l cili i , f o hic h

ars ar s re inae h as een rn awa . ar r us are p cili i t b to y g Cili y body (co p cili ) . i r i r ea : th u r r h Scl erotic (s cl e ra) . Cho io d (cho ioid ) e s p acho ioid al l ay er is r na ars a la ma n f r n e . Re s o a a er t rn well s ee . j Thick ti (p optic ) i hy loid t y o n eri r away a t o ly. PLATE 1 9

erior sur a e of th e e e a th e rn ea a in en cu t View of th e ant f c y b ll, co h v g b e

m er a en . away an d th e an terior ch a b l id op

in e e w ere th e orn ea h as ee n cut awa on th e r U n der th e th dg , h c b y ight arat n s ome th e res th e e in a e i amen can be s ide of th e prep io , of fib of p ct t l g t th e s a es n an in n wi th e o en in s a e ween em . s ee , (g) th p g of p c of Fo t b t th

O s ero s era . b Cu t e e u ar n un i a a uter s urface of cl tic ( cl ) dg of oc l co j ct v .

- cut rou an d rn ea re m d n r r c Scl ero corn eal margi n th gh co oved . A te io n r r w t an r r s u r a i i in u a e e o e r s e . ch amb er (camera oc li t io ), i h t i f c of b h d i i mar u ar s ri s . n e Pupill ary margin of iris ( go p pill di ) f L e s (len s crys talli n a) u res th e e n a e i amen amen um seen through p pil . g Fib of p cti t l g t (lig t ti natum ri is w en in s of th e a es n an a s at a an u i p ec i d ) , ith op g Sp c of Fo t ( p i g l ri z a a i is h r u ar s s . R s of r s ae r s . i rid ) . Ci c l fold of i di l fold i (plic i idi ) PLATE 20

n eri r ew of th e e e the orn ea an d s e r a in e e en r m . A t o vi y , c cl otic h v g b oved

Th e an u us ri s is us e ose from th e r n c an d th e res ass n g l i di th xp d f o t ( ), fib p i g rom th e orn ea th e ron th e i ris w i on s i u e h e i amen um f c to f t of , h ch c t t t t l g t ectinatum ri s are we is a e i n th e in er s e ween s r s p i di , ll d pl y d ; t val b t th e e fib e — ere are o en n s ea in in o th e r - e s a es th e s a es of o n tana th p i g l d g t c ypt lik p c p c F . r "u st extern al to t h e margo ciliaris o f th e iris (c) may be s een a n arrow annu lar ban d s u rroun din g th e i ris : this marks th e anterior attachmen t of th e meri dio nal fib res of th e ciliary muscle to th e in tern al scleral p rocess (ligamen t um an n u are l ) .

a Chorioid (chorioidea) b Scleral s urface of th e ciliary body (corpus i iare c Mar s th e s n th e a e n an a s a a an u i r . s s c l ) k po itio of Sp c of Fo t ( p ti g l i idi ) , th e op en ings of which appe ar b etwee n th e fibres of t h e p ectin at e ligamen t r rn ma be e en the n (ligamentum pectin atum i idis) . "ust exte al to c y s li e of n h an e ri r e n s h m ri n re th e iar mu attachme t of t e t o d of t e e dio al fib s of cil y scl e . h d Co nvexity of th e i ris overlyin g the Sphin cter p upillae . e T e pupillary

m u ri r i n . margin of th e i ri s ( argo p pilla s i id s ) . f Len s s ee through p upil

r . g Circu lar folds of th e i ris . h R adial folds of th e i ris (plicae i idis) i Ve nae th r n erior i r r r ar ria i iaris vorticosae of e cho oid . j Lo g pos t c lia y a te y ( te c l

i i r n . i ri . p ost erior l onga) . h C l a y n erve ( c li a s)

PLATE 22

n eri or i ew of e a e ee i men iri A t v d t ch d d ply p g ted s .

Th e u d is airl wi e a e its os e ri r mar n is in an d s ar p pil ( ) f y d ly dil t d, p t o gi th h p, but its e ern a ircum eren e is t i an d e e e as s een in s a ow on xt l c f c h ck b v ll d, h d t h e ri s i f h Th ght d e o t e specimen . e c on cen tric fu rrowing (e) of th e anterior s ur a e i we mar e as ar s e a s th e ra ia i ae b . f c ll k d , l o d l pl c ( )

a Extern al margi n of I ris torn away from th e ar body (margo ciliaris o cili y i ri b a a i a . . dis) . R di l pl c c P upill ary margi n of I ris (margo pupillaris i ridis) d u i ar a ert ure u a e n r P p ll y p (p pill ) . Co cent ic plicae . PLATE 2 3

s eri r s ur a e of th iri Vi ew of th e po t o f c e detach ed s .

i f rm h n erior wa of th e s erior am r O in th e Th s o s t e a t ll po t ch b e . w g to p resen ce of th e d eeply pigmen ted uveal layer (pars i ridica retin ae o r s tratum pigmen ti i ridis) this surface is difficult to photograph an d th e details of its Nu mer u r ia t stru ctu re are n ec essarily ob scure . o s ad l folds ( he s tr uctur al f olds of Schwalbe) are s een p ass ing from th e ciliary attachment in ward s ar s th u b me ese f s are s een t rn a r s s at th e u er tow d e p pil ( ) . So of th old o c o pp ar th e ar mar in an d t e r res en e is du e th e irre u ar u n e of p t of cili y g , to h i p c g l o tli

u 1 . th e i n n er edge of th e torn ciliary bord er . Abo t mm from th e pupillary t s ar s are r a e n umer us s ma er n e e dge h e e l ge fold epl c d by o ll o es (e) . Th se

are th e s o - a e contraction olds wa e an d orm th e u i ar n e c ll d f of Sch lb , f p p ll y zo

( Fuchs) . i a i ar mar n ir s rn rou mar ar s r s . Th e n n er C li y gi of i , to th gh ( go cili i idi ) i e e s mar n is irre u ar in u n e due th e s ru ura f s e n dg of thi gi g l o tli , to t ct l old b i g rn a r s b s er r su r a e I r s ere w th e u ea a er f rm t o c o s . Po t io f c of i cov d ith v l l y o ed by th e p ars i ridic a retin ae ; h ere th e s tructu ral folds passin g from th e Ciliary u i r r m bord er i nwards to th e pupil may be s een . c P p lla y ma gin ( argo pupil ar s r s as s een r m e n s is a t in e e w a n e ren ate l i i idi ) f o b hi d, thi h dg ith fi ly c d '

r r a u i ar a ert ure u a . e ain s een are th e fin e f bo de . P p ll y p (p pill ) F tly olds i (co ntraction folds of Schwalb e) forming th e pup llary zon e of Fu chs . PLATE 24

iew of the an er or sur a e the e e th e s ero i an d rn ea a in V t i f c of y , cl t c co h v g n m bee re ove d . Th e right half of th e i ri s h as been cut away so as to op en th e posterior hambe r th e os erior wa w i i s us e ose is is s een be c , p t ll of h ch th xp d ; th to formed from Without inwards by the blu nt anterior extremities of th e ciliary ro esses e th e onu e of nn onu a i aris d m se th e res p c ( ) , z l Zi (z l c li ) ( ) , co po d of fib c form th e am n of th n n i r u h ns whi h lig e t e l e s ; a d th e anter o s rface of t e l e (f) . Th e cut e e th e i iar mar in o f th e ir s c is s own an d ert ain n arr w dg of c l y g i ( ) h , c o f ar n i e ar th r n e s i ass olds ( j) e s ee d vided . Th se e e adially arra g d fold wh ch p from th e fore part of the ciliary b ody an d ciliary processes o n to th e posterior

sur a e o f th e ri s n er i n owar s th e u ar mar in see Pls . 2 f c i , co v g g t d p pill y g ( 4 , On the left and upper sid e of th e p reparation th e outer l ayer of th e ciliary bo dy h as been dis sected away S O as to expos e th e meridi onal fibres of th e Ciliary mus an d th e as u ar an d n u it in it s u s an e os e to cl e v c l ervo s plexuses w h s b t c . Cl t h e ciliary margin of the iris on the left s ide can be seen some of t h e fibres of h t e p ecti n ate ligament and the Open in gs of the spaces of Fontan a.

a i i b M r i na re i ia mus e o er or o or o ea . e s r e Ch i d (ch i d ) id o l fib of c l y cl , t g th i i ar w esse s and n er e . ut r ra m n I r s mar s th v l v s c C pe iphe l attach e t of ( go cili i ) . d n u f in n us n am n f h ns e n er r remi e o e o s e sor e o t e e . e s Z l Z , p y lig t l A t io xt ti h i n n s r i u i r s a na . of t e cil a y processes seen i n s hadow. f Le s (le c y t ll ) g P p l ar mar i n of I ris mar o u ar is h i res th e e n a e i amen w l y g ( g p pill ) . F b of p cti t l g t ith th n f u iri i Cut e e e ope ings of th e s paces o Fon tana (spatia ang li dis) . dg ir s cut ass n fr m i iar o an d ro es ses t o s eri r of is . j Fold p i g o c l y b dy p c po t o rf r u 13 u r u f ar su ace of i is (struct ral fold s of Schwalbe) . O te s rfac e o cili y body i i rm u . m e (corpus ciliare) . "Ciliary n erves break ng up to fo pl ex s D vid d

edg e where superficial part of ciliary body h as been removed . PLATE 25

s i im n PI 2 e a h i ri h as now een s th e same e e as . e t e s Thi Sp c 4, xc pt th t b

om e e remo e us a n o en th e w o e of th e os erior am er . c pl t ly v d, th l yi g p h l p t ch b

Th e en s in th e n re is s us e n e its i am n n u e of inn th e l c e t p d d by l g e t (zo l Z ) , res o f w i are faint si e in th e s a ow su rroun in th e ens assin fib h ch ly vi bl h d d g l , p g from the ci rcumferen c e of th e len s towards t he in ner surface of th e ciliary body ; th e rou n ded en d s of th e ciliary processes are dimly s een o n a plan e an eri r h n inn In fr n ese are s e n a n um e r of n t o to t e zo ule of Z . o t of th e b thi w i w e r e n o s . ese are the s ru ura fo s of wa be hit p oj cti g f ld Th t ct l ld Sch l , h ch h ave been divide d as they pass from th e fore p art of th e ciliary body and th e s ame p rocesses to th e posterior s u rface of the iris . Th e other details are in 1 as PI. 9 .

a r oi r b M r n a res f i iar mus e o e e r o ea . e o Cho i d (ch ioid ) idio l fib c l y cl , t g th i es e s an d n u ri ra a a m n iris mar ar s w th v s l erves . c C t p e ph e l tt ch e t of ( go cili i

d onu e in n u n a n f n s n in s a ow. i ridis) . Z l of Z ; s spe sory lig me t o l e s ee h d e n erior roun e e remi ies of th e Ci iar ro esses r essus iares s een A t d d xt t l y p c (p oc cil ) , f a ens s i a . u a s o in s h d ow. f L (l en c rystall n ) g Divid e d folds (stru ct r l fold wa e assin fr m re ar of i iar o an d i iar ro ess th e Sch lb ), p g o fo p t c l y b dy c l y p c to

er surfa . us post i or ce of th e iris h Ciliary n erves b reakin g up to form plex . i O uter (scleral) s urface of ciliary body ; n ear this the cut edge is seen where h su er a r h a n m i t e p fici l laye s bee re oved to expos e th e c liary muscl e . PLATE 26

ew of th an r r f u - i us Vi e te io s urfac e o f th e eye o a f ll t me foet .

Th e rn ea an d s er a in een remo e th e an er or am er is co cl otic h v g b v d, t i ch b a en an d th e an u us iri e i u se ere s me th e res l id op g l dis ( ) s th s exp o d . H o of fib th e am en um ectin at um ri is are e ose wi th e en in s e ween of lig t p i d xp d, th op g b t t em th e s a es of on tan a s a ia an u iri s ese we er are h of p c F ( p t g li di ) ; th , ho v , e er s i P 0 m ar in of th e een n I. 2 mm i t a a e b tt . I ed ate ly e xtern al to h e tt ch d g iris mar i aris is an ann u ar an of issue s me imes a e th e ann u ar ( go c li ) l b d t , o t c ll d l i amen amen u m an nu are an n u us t endin osus r m w th e mer l g t (lig t l , l ) , f o hich i dion al res th e i ar mus e ari s e fib of c li y cl . is re ara i n ewis e ows th e ra ia ar er es th e iris e as s n Th p p t o lik Sh d l t i of ( ) , p i g from th e circulus maj or e xtern ally to th e circu lus min or n ear th e pupillary e dge .

a r oi r n or s era s u r a e th e iar Cho i d (cho ioid ea) . b Exter al cl l f c of cil y d r s r us u an n u are . e body (co p ciliare) . c An n ular ligamen t (ligamen t m l ) Fib e n a e i amen amen um e ctin atum e ween w i are t h e of p cti t l g t (lig t p ) , b t h ch n n s e a a f s ope i g of th e s p aces of Fo n tan a (spati a angu li iridis) . R di l old in which may be s e en vesse ls pass i ng from th e circu l us major extern ally th e r u us m n or n ear h u ar e n eri r sur a e of i ri s to ci c l i t e p pill y edg . f A t o f c , m n a n a s een r s er r a . n s en s r s fo i g po t io w ll of an te rior ch amber g Le (l c y t lli ) , i n r u the u h u i a mar n r s mar u i aris . th o gh p pil . P p ll ry gi of i i ( go p p ll ) Lo g

s er r i iar arter . i ar n r e po t io c l y y j C li y e v . PLATE 27

ew of th e an eri r sur a e th e e e th e orn ea an d a rin Vi t o f c of y , c g of s clerotic

h avi ng b een removed .

t rn a a Th r r Th e i ri s h as als o b een compl etely o w y. e po ste io ch amb er is Th e en s surr u n e th e on u e of in n i u e ose . s we S wn f lly xp d l , o d d by z l Z , ll ho ,

an t r n t r r s s s t ere o is ear s een Th d h e el atio of h e cilia y p oce e h t cl ly . e Sp ecimen h as b een photograph e d by a combin ation of refl ected an d t ran smitte d light ; th e atter in es t r u th e anter r a of th e e th e e e w h as l Sh h o gh io h lf glob of y , hich e n i u ria In t s wa th e etai s of th e i amen b e div d ed eq ato lly . hi y d l l g t of th e len s n (zo u l e of Zin n) are better displayed .

a t e rn a sur a e an d s er i s era . b Cut e e of s er t w c Ex l f c cl ot c ( cl ) dg cl o ic, hi h

a h r - rn ea un i n c or ar f h h s b een divide d wid e of t e s cl e o co l j ct o . F e p t o t e

e ern a sur a e th e iar r us are e se . d en s en s xt l f c of cil y body (co p cili ) , xpo d L (l r r in a th e an eri r r m ies f h i i r sta n a . e u e s e e o t e a c y lli ) Fig d olid bl ck , t o xt it c l y u i r n t h i m r esses r es s s ares w e e s er or a er . p oc (p oc cili ) , h ch p oj ct i to po t ch b res th e s us en s or amen n u a iaris ass n r m th e in n er f Fib of p y lig t (zo l cil ) , p i g f o r i i r ren t A s u fac e of th e c l a y body to th e ci rcumfe ce of h e len s . s will be s een rom an ins e i n of th e o ra s ereos i al ese do n ot all lie f p ct o phot g ph t cop c ly, th n th e s m an e i a e pl . PLATE 28

ie o h r h w f an r o a f e e e . ame s im t e e s e o t e en as P1 2 . V t i p ct y S p c . 9

’ Th e cornea h as een remo e at th e e ro - rn ea un i n and th e iris b v d Scl co l j ct o , h as een om e e ta en awa t us o en in u the os erio r am er and b c pl t ly k y, h p g p p t ch b , e osin its os eri r wa o rme rom wi ou i nwar s th e an er or xp g p t o ll, f d f th t d by t i e remi ies th e r r esses th e onu e o f inn and th e an er or xt t of cilia y p oc (f ), z l Z , t i s u r ace o f the en Th res o f th e on u e are we s een and o n the ef s . e f l fib z l ll , l t Side of the specimen a faint Sh ad ow cast by th e l en s is s een on th e anterior s urfa e of th e i r us c v t eo . i a b u ar on un a . c er ra . O Extern al surface of s clerotic (scl e ) c l c j ctiv Scl ot c , cu t ose t o s ero- rn ea u n i n d n u e of in n wi th e res th e cl cl c o l j ct o Zo l Z , th fib of n e e n s i s o s i men s uspe ns ory ligamen t of th e l ens faIntly s ee . L w th p t of p g t r h e ris n eri r i ndicatin g th e p os ition of th e pupillary ma gin of t i . f A t o r us ar ext emities of th e ciliary p rocesses (process cili es) .

PLATE 3 0

Th m imen as 2 i ran m n e sa e s e a es 8 an d 2 ewe s e . p c Pl t 9, v d by t itt d light o ly

Th e rn ea an d i ris a een r Th e ear rin rres n s th e co h ve b emoved . cl g co po d to zonu l e of Zi n n (d) and exhibits th e fai nt s tri atio n due to th e fibres of th e s us ens r amen of t h n t e rna th e n u e is m e b th e p o y lig t e l e s . Ex lly zo l li it d y i rr e u ar ou n e th e i iar r ess es b w s in e rn a its e e orre g l tli of c l y p oc ( ), hil t t lly dg c s o n ds t o th e i r umfe ren e o f th e en s c p c c c l ( ) .

b r u a u a e r ti o ere an eri r th e u ar n u n a . r e r o t Scl o c , c v d t o ly by oc l co j ctiv I g l li n e due to th e p roj e ction of th e a nterior extremities of t h e cili ary p rocesses r essu s ares c Th e n n r s a na th e e e a ears re n a e (p oc cili ) . l e s (le s c y t lli ) dg pp c t d d n wh ere th e fibres of th e s uspen s ory ligament are attached to it. Zo ule of Zi n n (zo n u la cili aris) ; th e fain tly s triate d appearan ce is due to th e fi bres of th e sus ens r ame n of th e en s p o y lig t l . PLATE 3 1

of th e an er or as e of the e o f th e e e the rn ea ar of th e View t i p ct glob y co , p t h m s er an d th e w o e t e iris a n een re o e . cl otic, h l of h vi g b v d Th e posterio r ch amber i s fully exposed th e s tru ctu res which lie in relation i r r wa are u s een th an n s f th e i ar ro to ts s e . e er r e o p o t io ll f lly , viz t io d c li y p ess es e ern a ( the on u e in n w th e res of th e su s en sor a c xt lly f), z l of Z ith fib p y lig men of th e en s h an d th e an er r s u r a e of th e en s in ern a . Th e t l ( ) , t io f c l t lly (g ) an er r ar th e s era s ur a e of th e ar o is a so s een an d the e e t io p t of cl l f c cili y b dy l , dg w ere th e iris h as een orn awa e i n h b t y ( ) s Sh ow .

i a r in th a O uter s u rfac e of s clerotic (s cle ra) . b Ocu l ar conj unct v ove ly g e

Cut i - n n d era er c e e s e r r n a u . s cl otic . dg of cl ot c wid e of s cle o cor e l j ctio Scl l s ur a e an r r ar f r e e w ere r s h as f c of te io p t o cili a y b ody (corpu s cili are) . Edg h i i een rn awa r m ar n r u n e e trem ies of t h e b to y f o cili y body . f A terio ro d d x it ar r ess es r essus ar i sur a e th e ens w es . n er r cili y p oc (p oc cili ) g A t o f c of l , ith m s o e pigme n t adh erent to it d erive d from th e p upillary margin of th e i ris . h Zon u le of Zin n (zon ul a cili aris) th e fibres of th e s uspen s o ry ligament of th e en s are ear wn an d t e r a a men t o th e ir u m eren e th e en s l cl ly Sho , h i tt ch t c c f c of l , w r t f m a n th f s e e e r re a e e e i s we s een . i On e or two e h h y o c t d dg , ll of old st ru t ura s wa e as s n r m th e i ar th e s e r r ( c l fold of Sch lb ) , p i g f o c li y body to po t io s u rfa e th e r s are wn t rn a r ss . c of i i , Sho o c o PLATE 3 2

View of th e anterior s urface of th e glob e of th e eye of an eighth - mon th

foet us .

Th rn ea and ir n m n t s eri r ch amb er e s e e co is h ave bee re oved a d h e po t o xp o d . Th e specimen h as b een photograph e d by a combin ation of both refl ected and ran smi e so a th e n u e in n a ears as a rin t tt d light, th t zo l of Z pp light g ween th e en s an d th ar ro sse Th e res th e amen th e bet l e cili y p ce s . fib of lig t of l en s are visible as a s eries o f fi ne striae radi ally disposed ; it i s wort hy of n ote th at th eir attachmen t to th e circumfe ren ce of th e len s is n ot marked by an ren a ion th e mar in as s een in the er s e imen s due ro a y c t of g old p c , p b bly t o th e fact th at these attachmen ts h ave n ot been straine d by th e u s e o f th e me an ism o f a mm a n ch cco od tio .

a ern a s ur a e s r s era b i i e e e of s eroti Ext l f c of cl e otic ( cl ) . Th ck div d d dg cl c

n ear s er - orn ea u n i n c en s e n s r s a in a ain mar e w ur cl o c l j ct o . L (l c y t ll ), f tly k d ith fo ra a s tr a d i r n i in e . o n u e n n n u a i ar s w a a s r ae a di l i Z l of Zi (zo l c li i ) , th di l t i i d c t g t he res th e s us en s m n th e ns e ar r es ses ro fib of p ory liga e t of e l . Cili y p oc (p ces u s s cili ares) .

i ew th e in e r or th e an erior a o f th e e o f th e e e t a en V of t i of t h lf glob y , k by r e e e fl ct d light .

In th e en re i s th e ens su rr u n e th e n u e in n i n ee a w c t l , o d d by zo l of Z d p Sh do on ly very s light suggestion s o f th e striate d arran gement of th e s us pe n s ory n n n b n u rr un in th e ar nu e i s h e r n a ligame t of th e l e s ca e se e . S o d g d k zo l t co o

is m a u o f en - ei ar s ses i n t s e men In is ar e se r e . cili , d p v ty ght cili y p oc hi Sp ci th p rep aration th e ciliary proces s es are n ot all e qu al in s ize ; l arge an d small n r " n th e s eem a ern a e art u ar i th e u er ar th e o n a . e wee to lt t , p ic l ly pp p t of c o t

cor on a an d th e ora s errata th e orbic u lus ciliari s with its radial stri ae is visible . The s i n th e o ra s errat a is a aren t an d it s n e r er is we po it o of pp , otch d bo d ll

displaye d in th e u pp er p art of th e spe cim en .

a er ra b R e n ars a . c O ra s er ra a . d O r Scl otic (s cl e ) . ti a (p optic ) t bi

- lu . u n r c u s aris e r n a ar s ma e s e e e a r es ses . cili Co o cili i , d p of v ty ight cili y p oc r f Poste rior s urfac e of th e le ns (l e n s crystalli n a) . g Cili ary p roces s (p oce s s us

i iar s h n u n n n u a ar s . i r ri e a . c l i ) . Z o l e of Zi (zo l cili i ) Cho ioid (cho oid ) PLATE 3 5

th e n er r th e an er or a of th e e th e e e ewe b Vi ew of i t io of t i h lf glob of y , vi d y 1 refl ected light : th e s ame Spe cimen as Plate 3 . In th e cen tre is seen th e len s ; arou n d its circumferen ce th ere i s a n arrow

ar ann u ar n e th e on u e of in n ere an d t ere th e s tr at n r u ed d k l zo , z l Z h h i io p od c n can n rn a to by th e fibres of th e s u sp en s ory ligame t be fai tly s een (e) . Ext e l th e n u e t h e r n a ar s rme s e en o r m re ar r esse s is zo l , co o cili i , fo d by v ty o cili y p oc , ’ e s n W i e th e e e a n s r u e th e ar w ll di playe d (a a d i ) . d of l v tio p od c d by cili y e s r n i p rocesse s th e o rbic u lu s cili aris is s hown . Th o ra e rata of th e reti a s s omewh at obscured by t h e puckerin g of th e hyaloid membran e of th e vitre ous

body.

a S l ro ic s cle ra b h ri id h o ri i a ti r a r n c e t C o o c o de . c R n a a s o e a . ( ) . ( ) e (p ptic ti e) d O r i u us ar e n u e n n n u a ar s : th res th e b c l cili i s . Zo l of Zi (zo l cili i ) e fib of su s e n s r i amen t th en s can be a n t s e en s eri r s u r a e p o y l g of e l f i ly . f Po t o f c of th e len s (lens crystalli n a) along its ci rcumfere n c e m ay be s een th e p oi nt s of att a me n s m th e u s n s r r Th f rme e s e es . e r n a ar s o ch t of o of p o y fib g co o cili i , d

th e e t - o n ar r es r n h Th e r u s an d u re by igh y e cili y p oc s es h e e p re s e t . vit e o p cke d a m m ran i i r e ar r ss r ess us a s . hy loid b e . Cili y p oc e (p oc c li i ) PLATE 3 6

i w i r r th e an V e of th e i nte r o of th e ante io r h alf of e glob of ad ult eye . This photograph h as b een i ntrod uced b ec aus e it Shows very well th e arran e me n th e ame ae th e en s as s een r m e n rm th e s e r r g t of l ll of l , f o b hi d, to fo po t io ens s ar A b n in t e m n th e s su f th e n is s s . s w e s ee s s e e o e s o e l t ill hi p ci , ti l di p d

i n e we - a mas s es ight dge s h ped .

Th e len s als o di spl ays aro un d its circu mfe re n c e th e two - e dged app earance e e i n a e Th itre u s an d a i mem ran e a e e e n xhibit d Pl t 39 . e v o hy lo d b h v b rem e fr m th e os eri r s u r a e t h e e ns bu t th e n n e n th e two ov d o p t o f c of l , co xio of

seems to corre spon d t o th e pos te rio r e dge of th e ci rcum fe ren ce of th e le n s . To t h e anteri or margi n of th e ci rc um fere n ce m ay be s ee n p as s i ng th e fibres of th e s u s en s r amen th e e n s p o y lig t of l .

a e r s era b rn e e th e a m em ran e c r n a Scl otic ( cl ) . To dg of hy loid b . Co o ’ iar m - s r s u ares a n s r e e o n e ar r es es e s s . u e cil i , fo d of ighty cili y p oc (p oc cili ) Zo l of Zi n n (zon u l a cili aris ) ; th e fibres of th e s us p e n s o ry ligame n t of th e l en s are re s ee n ass n t h e a n te r r a s e th e r u m eren e th en h e p i g to io p ct of ci c f c of e l s . s r a h e n s e n s r s ta n a w n th e n s s ar e e r s u r e t e e . Po t io f c of l (l c y lli ) . Sho i g l t R in R n a r u u aris et a ar i a e a d s r e s . f (p s opt c ) . g idg d t i t d o bic l cili

PLATE 3 8

View of th e in te ri or of th e anterior h alf of th e glob e of t h e eye of a fu ll s term foetu . Th e retin a is thick an d fl es hy looki n g ; at th e margin of th e o ra s errata it r u n n H o far t es a aran es are du e s form s a o d e d swo ll e edge . w h e pp e c to po t m a n r h n u n s res e r a n i u n rta n s s a e mo rte ch ges o t e i fl e ce of p v tio s ce i . At thi t g n r a u re s me th e vas c u l arity of th e reti n a is well displ aye d . A oth e fe t of o i ntere st is th at th e z on u le of Zi n n is represen te d by but a n arr ow d ark r in g

n Th e a r ar s n - five m e rou th e ens . r esses w ere e e e d l cili y p oc , of hich th v ty , co n ar r th r u m r n th n an i n th a u In t s ase th e much e e e ci c fe e ce of e l e s th e d lt . hi c

- po sterior su rface of th e l en s exhibits a four fi ss u red app earan c e .

r t b r t n a rs a . c r u us ar s . a Scle o ic (s clera) . Thick e i (pa optic ) O bic l cili i

- d r n a ar s ma e u s e e n five ar r es s es . e s er r Co o cili i , d p of v ty cili y p oc Po t io i i s u an su r a e en s e n s r s a n a w e e n e ur ssu res n ts s e . f c of l (l c y t lli ), ith vid c of fo fi b t c nu e n n n u a ar s e re s een as a n arr w n er a e we en th e f Zo l of Zi (zo l cili i ) , h o i t v l b t m re n e r w e n e e ars ci rc u fe c of th e l en s an d th e cili a y proc es ses . g S oll dg of p

r h r r o a . opt ic a eti n ae wh ere it fo rms th e o ra s errat a . Cho ioid (cho i ide ) PLATE 3 9

h View of th e inte rior of th e anterior h alf of t e glob e o f th e eye .

n n mi T rn a Photograph e d by combin e d re fl ected a d tra s tte d light . h e co e r n Th n u i n i an d i is h ave been removed from th e fron t of th e l e s . e zo l e of Z n s s ee n as a ain s ria e an n u ar n e su rr un n th e ar er en s i n th e light, f tly t t d , l zo o di g d k l en re th e re ara n Th e r um e ren e th e en s s a s an an e r r c t of p p tio . ci c f c of l di pl y t io and s er r e e w are a a e t h e res th e an ter o r and po t io dg , to hich tt ch d fib of i posterio r l amellae of th e zonu l e of Zin n resp e ctive ly ; t h es e e dges h ere an d ere n h e re t h s us n r m n t th Show th e poi n ted attachme ts of t fib s of e pe s o y liga e . ern a th e on u e is th e r n th e r n a ar s rme i n t s Ext l to z l i g of co o cili i , fo d hi s e s Th e r u u aris is n o t p cimen by eighty folds o r cili ary p roc ess e . o bic l s cili w Th re u h m e s een an d th e o ra s erra a is s u re . e s as een re e ll , t ob c vit o b ov d, but h ere an d t h ere patch es of hyaloid membran e still remai n attach ed to th e n n er sur a e th e re n a i f c of ti .

a er i s a b R n a ars i a . c ws a a a Scl ot c ( cler ) . eti (p opt c ) Sho p tch of hy loid m em ran rm i n s n s tan e e a a e th e re n a . d r n a ar s e b tt ch d to ti Co o cili i , fo d thi i c e f th n i r um ere n e ar r ess es . e s er r s u r a e o e e s ts by ighty cili y p oc Po t io f c l , ci c f c mar t i ar ke d by h e attachmen t of th e fib res of th e ligame n t of th e l en s . f C li y r ess r es sus ar s n u e o in n n u a ar s s a n th e p oc (p oc cili i ) . g Zo l (zo l cili i ) , di pl yi g res th u n s h n s h ar th e r u u s ar s fib of e s s pe ory ligame n t of t e l e . P t of o bic l cili i is er s n i Th e r r ea s e en e ween th e s era an d re in a . h e ee . cho ioid (cho ioid ) b t cl t PLATE 4 0

ew of th e n e r r th e an er or a th e e th e e e a en b Vi i t io of t i h lf of glob of y , t k y r e e m m n e am e an d r n s e . Th s imen a . fl ct d t a itt d light co bi d e s e p ec s PI. 39

In th e e n re is th e en s s u rr u n e a n e s tria e n e th e c t l , o d d by light fi ly t d zo , zon u l e of Zi n n ; h ere th e tran smitted light s hows up we ll th e fibres of th e s u sp e n s ory ligamen t (th e corn ea and i ri s h ave b ee n r emove d fr om th e fron t of t h n W i th e n u i th e r n a i aris orm e i t i ei e e s . e e s n s as e l ) d of zo l co o c li , f d h c by ghty ar h n ma b h r u us i iaris h r esses . ern a t e or a e seen t e cili y p oc Ext l to c o y o bic l c l ( ) , an d w e a th e en e ra n e th e o ra s erra a can be s ern e u id of th t g l li of t di c d, tho gh s m r u an d it i to o e exten t ob s cu re d by th e vit e o s s hyalo d memb ran e (h) .

a . ra c r u an d a i R etina (pars optica) b Scl erotic (s cl e ) . Vit e o s hy lo d m m r n d n u e n n n u a ar s w th r h e s us en e a e . e es t b Zo l of Zi (zo l cili i ) , ith fib of p s o ry ligament p as si n g from th e Cili ary body t o th e len s wh ere they are attach e d th a h a u n i r an d e r to e l tter t e c ps le of th e l e s s h e e th e el evate d an d i rre gu lar. e ar i s e r r s ur a th n s en s Cili y proc es s (process us cili ar s) . f Po t io f c e of e l e (l r s a n a oron a iaris ma e u ei C ar r es s es s ur c y t lli ) . g C cil , d p of ghty ili y p oc rou n in th e n u e n n h O r u us ar s i r r ea d g zo l of Zi . bic l cili i . Cho ioid (cho ioid ) .

PLATE 4 2

Vi ew of th e i n terior of th e ante rio r th ree - qu arters of th e globe of th e eye

- Th e s am e s e men as P1. 2 t f e t u s . of an eight h mon h o . p ci 3 Th e corn ea an d i ris h ave b e en r e move d s o t h at th e s p e cime n cou ld b e n a n re e e an d t r n sm tt Th m photog raph ed by a combi tio of fl ct d a i e d light . e ost n otic eable feature abo ut this vi ew is th e red un d an cy of th e reti n a ; h ow m uch

of th is foldi n g an d p uck erin g is du e to pos t- mortem changes or th e e ffects of th e re a en s em e is iffi u e erm n e bu t ma be in te ou t g t ploy d it d c lt to d t i , it y po d n n a wee n t a re res en i n PI 1 a is a s a t ra s s e e te . th e th t it d pl y itio t g b t h t p d 7, ’ i an a a m n s e u s an d a s wn i n 1 h e f e e a s x d . t e e o y of h lf o th fo t , th t ho Pl 5, y

- r u a fu ll te m foet s .

d e r i ra . b an e n a c u n n a Scl erotic ( scl e ) Thick fold d t . Zo n le of Zi u r Th e e ate ra a res th e s us e n s r m n th e (zon l a cili a is) . d lic di l fib of p o y liga e t of l en s are reve al e d by th e tran s mitte d light : n ote th at th ere i s n o un even n e ss rr s n n t o t e r a a me n th e r um e ren e th n s d i iar co e po di g h i tt ch t to ci c f c of e l e . C l y

- r e ss es r es s u s ares s wn in s a w. e en s e ns r s a n a : p oc (p oc cili ) , ho h do L (l c y t lli ) is ar n ate r i r its mar e n e e . k d co v xity cl ly i dic d f Cho io d (cho ioid ea) . PLATE 4 3

ew th e in er r f th an r r Vi of t io o e te io h alf of th e eye .

Th e i re us an d en s a n een rem e th e os eri r am er th e v t o l h vi g b ov d, p t o ch b of a u eous am er is a en an d th e sterior or u ea s ur a e th e r s q ch b l id op , po v l f c of i i In th e en re is th e u i th ' h i h rn a is s een w is e se . i o u w t e o e xpo d c t p p l , g h ch c ith th a n s a w th e u ar mar n as n i W e of th e ris th e e f i t h do of p pill y gi c t o t . id i

- or na ar s is s een ma e u s e en se en ar r esses . Th e c o cili i , d p of v ty v cili y p oc

in tervals between th e l arges t folds seem tightly packe d with s maller folds . Ou s e th e ron a es th e r u us iari s an d e ern a a is th e o ra t id co li o bic l cil , xt l to th t

rra a n th e e e e th e re ara n h r in a is s e arate r m s e t . Alo g l ft dg of p p tio t e et p d f o h e ori t ch oid .

' b m n m a oi s a Sclerotic (s cl era) . Re ai s of s o e of th e vitreo us an d hy l d till r n a O r u ma e u a e th e . c us ar s d r n iar s a e i . o o a tt ch d to ti bic l cil i C cil i , d p of

e e n - se en ar ro ess es r e us iar e u i ar a ertu re s v ty v cili y p c (p oc s s cil es) . P p ll y p (pupill a) th e posterior s u r fac e of th e corn ea is seen th rough it ; th e pupillary mar in er n is s een be n e n e in rres n en e w th e g , v y thi , to fi ly otch d co po d c ith fi n e furrows an d folds which are di spose d o n th e p osterior s u rfa ce of th e iris i In a n th u ar n . r r r e p pill y zo e f Poste io o r u veal surface of t h e i is . good light this i s s een to be travers e d by radi al folds converging to th e pupil ; es e are th e s ru t u ra o s w R e na ars a h Ora th t c l f ld of Sch albe . g ti (p optic ) i r i ri e ra a o o a . s r t . Ch i d (cho oid e ) PLATE 4 4

iew of th e in erior of th e an eri r a th e e e th e v reous an d th e V t t o h lf of y , it n s a in l e h v g been removed .

Th e en posterior ch amb er of th e aqu e o us ch amber h as th us b een laid op . A n otewort hy feature of this s pe cimen is th e u npigmen ted con dition of th e r n h e iris i s co o a an d o rbicul us cili aris . Th e u veal s urface of th e b ack of t

ee u re . In th e en re th e a e r u re of th e u i is s een r u d ply colo d c t p t p p l , th o gh w i a a i r un h ch Sh dow s cast o n th e con c ave i nn er surfac e of th e corn ea. A o d th e pupil is th e broad d ark rin g form ed by th e pigmen te d p osteri or su rface th e ir s i e o r n o e a its s ru u re can be s een Th e oron a iar s of i ; l ttl d t il of t ct . c cil i

ies rn i ma e - r en n r m e e a s u s e ar o esses . l xt l to th , d p of ixty ight cili y p c Ext di g f o th e r n a t o th e o ra s erra a is th e r u us iar s th e s ria e arran emen co o t o bic l cil i , t t d g t of which is well displaye d th e mo re promi n en t fibres app ear to p as s fr om th e bas e of a ciliary p roces s to o n e of th e p oin ts which s eparate th e l u n u l es w i th e s erra e e e th e o ra is rme In e ween t es e m re of h ch t d dg of fo d . b t h o e i en res a n um er ara e s r ae ru n orwar to th e e e th e v d t fib , b of p ll l t i f d dg of or n a a n arrow m re o u re o n e a ears us in r n th e ora c o ; , o lightly c lo d z pp j t f o t of

s errata .

r b i i r u a er s e a . R e n a . c r r ea d O us Scl otic ( cl ) ti Cho o d (cho i oid ) . bic l

ar s . e u ar a e rt u re u a t r u w is s een th e s ter or cili i P pill y p (p pill ) , h o gh hich po i

s u r a e th e orn ea. U ea s ur e os er r as ris r na f c of c f v l fac of p t io p ect of i . g Co o

r s m r n s - i r h Ora a s e ar es s es r ess u s ares . cili i , co p i i g ixty ght cili y p oc (p oc cili ) erra a i Rema n s re us d a m m ran eren to s t . i of vit o an hy loid e b e s till adh t na reti .

PLATE 4 6

Vi ew of poste rior s u rface o f i ris an d ciliary body d eta ch ed from th e oth er ur th e stru ct es of gl ob e . Th e cili ary p roc esses an d th e o rbicu luS ' h ave b een bl each e d by th e action of r e r n s re a en es n o t a ear a e re m e th e pe oxid of hyd oge . Thi g t do pp to h v ov d men s o m e e r m th e s er r men e a er th e r s for pig t co pl t ly f o po t io pig t d l y of i i , r is m r e n s e Th e arran emen th e s o n th e s er r s u r a e h e e it o e d . g t of fold po t io f c

h e r s is we e n In th e u ar n e c n ear th e u i ar mar n t s e . of i i ll p pill y zo ( ) , p p ll y gi , th e fold s ar e fi n e an d very n ume rous : th es e con s titu te th e con traction folds wa e In th e ar n e d th e s ru u ra f s wa e are of Sch lb . cili y zo ( ) t ct l old of Sch lb s een radiati ng outward s an d d e ep e n i n g towards th e cili ary margin of th e r s e re an d ere th e u e a a e r o n th e s e r r s u r a e th e ir s i s i i . H th v l l y po t io f c of i n u re an d h i r su e en a i s n Th r n a ar s m a e t e e s e s e e . e i j d l ght ti b th co o cili i , d

- u s e e n on e ar r es ses ree r m e r men s an s o u t ear . p of v ty cili y p oc f d f o th i pig t, t d cl ly Fragme n ts of t h e to rn fib res of t h e s usp en s ory ligam e nt of th e l en s can h e re an d t ere be s ee n ar u n th e n n er m ar n th e r n a h o d i gi of co o .

a ar n e s r or s ur a e r s w s ru ura s wa e Cili y zo of po te i f c of i i ith t ct l fold ofSch lb . u ar n r r su r a e r s w fi n on b Pupil (p upill a) . c P pill y zo e of poste io f c of i i ith e c

d ar m n - o n r r ra n s . r n a s r e s e e e a e ss es t ctio fold Co o cili i , fo d by v ty cili y p oc r essus ar s (p oc cili e ) . PLATE 4 7

ew s er r s ur a e rn ea s er - o rn ea un i n an d n ern a Vi of po t io f c of co , cl o c l j ct o , i t l r i surface of anterior p art of s cl e ot c .

Th e s u us r u ar s rn eae b ar un th e s era r um eren e th e lc ci c l i co ( ) , o d cl l ci c f c of rn ea is we seen mme a e u s e a n arr w r n u n men e iss u e co , ll i di t ly o t id it o i g of pig t d t mar s th e s i n th e an nu ar ame n d to w th e amen um ec k po tio of l lig t ( ) , hich lig t p t in atu m of th e iris an d th e a nterio r i n s ertio n of th e meridion al fibres of t h e ar mus r a ern a t s t h e n n er s ur a e th e s cili y cl e a e ttach ed . Ext l to hi i f c of cl er otic i s e se w s me th e men e s s u e t h e am n a u s a w i con xpo d, ith o of pig t d ti of l i f c , h ch

n ects wi th e r s a ta e . it th cho oid , till t ch d

a r ra b u us r u ar s rn eae . c s er r s u r a Scl e otic (s cl e ) . S lc ci c l i co Po t io f c e o f rn e a rm n th e an er r wa th e an er r C am er ere th e s er r co , fo i g t io ll of t io h b h po t io i h n h r r a d rn s ur a l ami n a s wr i n kle d by t e actio of t e p es e v tive . To f c e of th e a n n u ar am en amen tu m an n u are t o w th e e n a e am n l lig t (lig l ) , hich p cti t lig e t th e ris an d th e m er n a re s th e ar m u s e are a a e of i idio l fib of cili y cl tt ch d . e r a s ur a e s er w t remain s o f th e men e am na u Cho ioid l f c of cl otic, i h pig t d l i f sca atta e ch d . PLATE 4 8

iew th e r n th e en s w th e a o mem ran e an d res th e V of f o t of l , ith hy l id b fib of s uspe n s ory ligament attach ed .

Th e re arati n h as een s a n e w er - n ros in an d o o ra e p p o b t i d ith pi o ig , ph t g ph d i by a c ombi natio n of re fl ecte d an d t ran s mitte d l ght . Th e hyaloid membran e (a) wh en viewed i n th e stereos cope is s een to be convex fo rward s aro un d th e l en s bu t th e len s i n den ts its anterior s ur face an d i th i i a r n Th m m ran s es n e ssa a e ar s w s e e . e e e a s li fo p t ll i , to h ch it dh t b di pl y th e m ress n s th e i iar r ess es on its sur a e t is i s es seen a o e i p io of c l y p oc f c h b t b v . R adial s tri ae als o i n dic ate th e p osition of th e fibres of th e susp en so ry ligamen t th e n s lie i i i e w n n a w ts an er r s urfa e . es e r of l , hich co t ct ith t o c Th fib es (b) are s een is n an d a ar rom th e mem rane o n a an e an er r it an d th d ti ct p t f b pl t io to , e maj ority of th em are cl ear ly s een pass ing to be attached to th e ci rc umferen c e h n su e n ear it an t er r mar in of t e l e s cap l s io g .

mem ran e b r s s us e n s r am n a a . e e th e e n Hy loid b Fib of p o y lig t of l s . Th e s a e e ween a an d b se th e r u m e ren e t h e en s rres n p c b t , clo to ci c f c of l , co po ds to

- th an a e . c n e r r s u r a e en s e so calle d c l of P tit A t io f c of l .

PLATE 5 0

iew of th e os e rior surface of th e en s - wi ar of th V p t l , th p t e hyaloid memb ran e s i a t ll att ch ed . Th e fibres of th e suspenso ry ligame nt are Cl early s ee n o n th e right s id e

th e s e imen w h as een s a n e w t icro - n i r s n an d o o r of p c , hich b t i d i h p g o i ph t g aph ed re e an d ransm e n is is th e same e m a by fl cte d t itt d light combi e d . Th Sp ci en s at s 8 and Pl e 4 49 . Th e hyaloid membran e h as been removed from th e r ight s ide of th e preparation ; it s ragged an d torn e dge i s seen wh ere it h as b ee n s trippe d o ff h n i i ren r m t h e os er or su r a e th e a su e t e e s to w t s a e . f o p t i f c of c p l of l , hich dh t In th e stereos cope th e fibres of t h e s usp en s ory ligamen t of th e l ens are seen i i r m r r m t h e d stin ctly n f o n t of th e u pper torn edge of th e hyaloid me b an e . F o n ear surfac e of th e hyaloid memb ran e there are n umerous ruptu red trabecu lae

passin g ; th ese have be en torn away from th e s ub stanc e of th e vitreou s .

a Hyaloid memb ran e . b To rn edge of th e hyaloid memb ran e wh ere it rms th e or th e ssa a e aris an d w er e it h as een s ri e o ff fr m fo flo of fo p t ll , h b t pp d o th e s er or s urfa e th e a su h e n s c s er r s ur a e en s po t i c of c p le of t e l . Po t io f c of l and a su e d res of th e s us ens r amen at a e t o th e ir um c p l . Fib p o y lig t t ch d c c

eren e of the ens a su e main n ear its an e r r or er. f c l c p l , ly t io b d PLATE 5 1

Two iews of th e fr n of th e en s wit ar of th e sus en s r amen v o t l , h p t p o y lig t at a e t ch d . In both instan ces a ring of pigmented spots o n th e su rface of th e l en s mar th i i f u i ar mar in in th e wer re ara i n due ks e pos t on o the p p ll y g ; lo p p t o ,

oss to os - m rt em an es ere is a m ar e n rease in th e on e i p ibly p t o ch g , th k d i c c v x ty th e an er or su rfa e of th e en s rres on n t o th e area r ums ri e of t i c l , co p di g ci c c b d by t h e u i ar mar In p p ll y g . I n s n th e ower s e imen a or ion of th e amen th e en s is see . l p c p t lig t of l Thi ,

at a is an e of a u 2 mm . rom the r u m eren e th e en s is s een t o d t c bo t f ci c f c of l , Con s s of a e a e trans aren mem ran e r a n nu u s os er or i t d lic t p t b , p ob bly co ti o p t i ly with the i nn er stratum of th e p ars ciliaris reti nae n earer th e l en s it b reak s u i n o a fin e re e mem ran e th e res o f w are s een t o be a a e p t Sh dd d b , fib hich tt ch d i n a n ear u if r in t th e an f r m r n e th e n ly n o m l e o terior port ion o the ci cu fe e c of l e s . On comparin g these Specimen s with t h e oth er ph otograph s in which th e amen th e en s is s own in s itu w be s een a t ere is n o t a lig t of l h , it ill th t h th t d epth and variation in th e pl anes of attachment of th e fibres of th e z on u la which is s o apparen t i n th e other p reparation s ; h ere seemi ngly we h ave to ea on w the an er or art th e n u e th e s eri r r n a n d l ly ith t i p of zo l , po t o po tio h vi g e en rem e n 2 b ov d . This is further explaine d i n Pl ates 49 a d 5 .

a few s a tere res th e s us en s r ame n of th e en s s een A c t d fib of p o y lig t l , a e b a at th e a su e of th e en s . c n eri r s ur a e of e n s w r n tt ch d to c p l l A t o f c l , ith i g men s s of pig t pot marki n g th e pos iti on of p upillary m argi n . d Anterior s urfac e en s s w n a m r w n th e m n t of l , ho i g o e mar ke d con vexity ithi pig e e d r i ng which mar s t h e r - k pos itio n of th e pupillary margin . W h eth e due t o post mortem C an e o r n o s a n n ates a th e r s can er i e s ome h g , thi ppeara ce i dic th t i i ex c s r es ra n n n u e t i i g i fl en ce o n th e con vexity of th e le ns . Fi n e fibres of th e an er r rt n o f th e n amen th e n s e se ar e n to be t io po io sus pe sory lig t of le . Th s ee er e rom th e s u r r n n n uou s mem r d iv d f plitt i ng p o s h eddi g of a co ti b an e at f . H 2 PLATE 5 2

ew th e ens wi ar s th e sus ensor amen on ne e w it . Vi of l , th p t of p y lig t c ct d ith U er s e imen is th e r n th e ens ower s e imen th e a pp p c f o t of l , l p c b ck

Th e an eri r sur a e the en s s wn in th e u er ri n is mar e t o f c of l , ho pp p t, k d by m r in a ring of pig en t spots which i n dicates th e position of th e pupillary ma g . Th e os er r s u r a e re resen e in th e wer u re h as s i flo ccular p t io f c , p t d lo fig , l ghtly a earan e as if n h d n rn awa rom is ere a th e pp c s omethi g a bee to y f it . It h th t e ns is in n a th i ran e th r Note ar u ar l co t ct with e hyalo d memb of e vit eous . p tic l ly th at there are n o i n dication s of d efi nite fibres h aving b een torn away from th e s er r as e its r um e r n e Th e res a a e in th e an eri r ar po t io p ct of ci c f e c . fib tt ch d t o p t th e r u m ere n e rm a er e n i e s r e e s ee th e amen s of w of ci c f c fo v y d fi t h dd d h t , fil t hich u n e e e rn a rm a e a e mem ran e in all ro a i i on nu us it xt lly to fo d lic t b , p b b l ty c ti o poste rio rly wit h th e i n tern al s tratum of th e p ars ciliaris retinae which ove rli es th e r u us an d ar ese are th e res of th e s us e n s r i amen o bic l cili y body . Th fib p o y l g t

th e e n s w i li i n - ana e of l h ch e n fro t of th e so call ed c l of P tit .

a a ere res th e s u s en s r i amen of th e ens a a e t h e Sc tt d fib of p o y l g t l , tt ch d to

ro n th e r umfere n e th e a su e . b n eri r s u r a e of th e en s wi f t of ci c c of c p l A t o f c l , th men mar s c n e s ria e mem ran e w pig t k Showi ng p ositi on of p upil . Fi t t d b hich e mes s re e n ear er th e en s d th e fin e is o a e res e n a a e b co h dd d l ( ), l t d fib b i g tt ch d e r e n t u f r n th a su e o f th e n s v y d fi itely to h e fro n t of th e ci rc m e e c e of e c p l le . e Posterio r s u rface of th e l ens ; thi s is seen to diS pla a delicate floccular

a earan e due r a its s e ara on rom t he h a oid mem rane . is pp c , p ob bly to p ti f y b It m ar e mor n n r k dly e co vex towards th e c e t e .

PLATE 5 4

i ew ransmi e i of th e ron of th e i iar o ens and sus en V , by t tt d l ght, f t c l y b dy, l , p n m r s or ame s e ara e ro th e o er s u ures the o e . y lig t, p t d f th t ct of gl b

Th e sp ecimen h as been stai n ed with pi cro - n igrosin s o as to ren der more in th r s h e u s n r amen In h r s e th e i er dist ct e fib e of t s pe so y lig t . t e ste eo cop d v gen c e of th e stran d s of th e s uspen s ory ligamen t as they pas s to th e circum fe ren ce of th e len s can be made ou t distinctly ; the angul ar i n terval separating

n h r m - n f i th em arou d t e ci cumfere nce of th e l en s for s the so Calle d c a al o Pet t .

i i b n r n a era s ur a e ar or us are . en s e s s a a Scl l f c of cil y body (c p cil ) L (l c y t lli ), s o deeply s tain ed as to be opaque : n ote h ere and there on th e circumference n a m n s th e r i a n n c ore ar th e poi te d ttach e t of fib es of th e l g me t of th e l e s . F p t of i ar r s ses ro essu i ar s d nu e of inn on u a i iari s : c li y p oce (p c s c li e ) . Zo l Z (z l c l ) t h e res th e am en th e en s are ee s ai n e an d s w u W e fib of lig t of l d ply t d, ho ll by In th e r s e it i s n a th e r s are transmitte d light . ste eo cop w ll be ee th t b e

rran e ra ia i n ff ren n "e wee n m runs th s o - a e an a a g d d lly di e t pla es . t the e c ll d c l r un th e ir m n h of Petit a o d c cu fere ce of t e lens . PLATE 5 5

ew ran smi e i of th e a of the i iar o ens an d s us en Vi , by t tt d l ght, b ck c l y b dy, l , p h s or amen s e ara e r m th e o er s ruc ures t e o e . y lig t , p t d f o th t t of gl b

The imen is th e same as a re res en e on a e an d h as een spec th t p t d Pl t 54, b

s tai ne d with piero - n igros in s o as to ren d er more distin ct th e s tructure of th e n Th e s re e a earan e o f th e amen of th e ens i s we zonu le of Zi n . h dd d pp c lig t l ll is a e an d w be a aren a all the res are not a a e i n th e d pl y d , it ill pp t th t fib tt ch d ir umf r n th e n s Th n er a aroun th e ir u m same plan e at th e c c e e ce of l e . e i t v l d c c fe rence of th e l en s b etween th e anterior an d poste rior main zones of attach

e res is th e s o - a e an a o f et n um r oi n m n t of th ese fib c ll d c l P it . At e ous p nts o th e r um eren e o f th e en s th e a su e of th e en s e i s ra on effe s ci c f c l , c p l l xhib t t cti ct rr es n n th e a a men th e res of th e sus en s r i a n co po di g to tt ch t of fib p o y l g me t .

a Zo nu le of Zin n (zonu la ciliaris) th e fibres of th e suspen sory ligamen t are n ar an AS w be s een i n th e s ereos o e s ome f h e r see ra a r e . o t es di lly g d ill t c p , fib

i r T a e n i th s - a e lie n f n th e ers . h e s e wee s e o an a of i o t of oth p c b t c ll d c l Pet t . b Len s (len s crystallin a) th e poi n ts of attachmen t of s ome of th e fibres of th e s uspen sory ligamen t are clearly in dicate d by e levate d points on th e circum f r n f h e n s c n r r m th e ar r e e c e o t l e . A terio ext e ities of cili y p ocesses (pro us i re d n n r u r f th r min r cess a s . e s a e o e a ere r th e ona c li ) I f c cili y body, h fo g co i aris Th e ai f h n . e s o t e ar r esses are n ot s e e w n th e fa c li d t l cili y p oc , o i g to ct th e im n n mi th at spec e h as bee photograph ed by tran s tted light . PLATE 5 6

Th e iar o on u e of in n an d t h e en s s e ara e rom th e o er cil y b dy, z l Z , l , p t d f th s ru tures the e e s aine w van G ieson an d o ra e from e in t c of y , t d ith , phot g ph d b h d r m i by t ans itted l ght.

In is s e imen In a ion th e ra ia res of th e onu e of inn th p c , ddit to d l fib z l Z , w i a e een am em n s ra e i n man th e er o o ra s ere h ch h v b ply d o t t d y of oth ph t g ph , th are er e ni e i n i a ion s ar i u ar in th e u er ar of th e on u e v y d fi t d c t , p t c l ly pp p t z l , of re a n a ir u ar i si i fib s h vi g c c l d spo t on .

a Plac ed where th e circu lar fib res of th e zonu le of Zin n (zon u l a ciliaris) are es is a e b onu e in n w th e ra a res of th e s u s en sor b t d pl y d . Z l of Z , ith di l fib p y i am n e n r t n a d Th e ar o r u s c n n s s a . l g e t of th e l s . Le s (l e c y lli ) cili yb dy (co p ciliare) : th e pr oj ection of th e an terior en d s of th e ciliary p roc ess es (proc essu s i i r i nu f n c l a es) form th e o uter n otch ed outl n e of th e zo l e o Zi n .

PLATE 5 8

View of t he interior of th e posterior h alf of th e globe o f th e eye of a child t o ears Th e ra was a en wen m n u es af er th e rem a w y old . photog ph t k t ty i t t ov l

of th e eye for an acciden t . Th e retina i s tran sl ucen t ; th e optic di s k an d th e macul a l utea are see n ; u n or una el th e s e imen is n ot s o rien e a th e two lie o n the same or f t t y, p c o t d th t h i z n t l an o a p l e . i i ri i Th e o i is a i a n . o ici w e i s e en e of i n eu s pt c d k (p p ll pt ), hich xh b t v d c opt c t , is seen wi a ir u ar er area i n the en re th e o rus us b th e th c c l light c t , p optic ( ) ; light and s h ade do n ot reveal the phys iological excavation (excavatio papillae n er i o i bu t the re ina esse s can be s een as two ar s o s a o e and v ptic ) , t l v l d k p t b v ru us a e e of h u below th e po s Optic s th y turn ove r th e e dg t e excavati on . Abo t mm r m th e e n re th e orus us th e u er e a ar s o mar s 4 . f o c t of p optic , to o t Sid , d k p t k t h e s i io n th e o ea en ra is c wit th e s i ar er e ow s po t of f v c t l ( ) , h l ghtly d k y ll pot m ( acula lutea) aro un d it . Th e re n a es se s are we is a e d th e e ns ein ar er an ti l v l ll d pl y d ( ) , v i b g d k th

th e arte ries .

a r r i ea . b O is a i a n o i i wi th e rus Cho ioid (cho io d ) ptic d k (p p ll . pt c ) , th p o opticus i n th e c entre imme diately above an d be l ow this th e re tin al vessels can be seen u rn n o er th e li o f th e a a i n c o ea en ra s : w n t i g v p exc v t o . F v c t li ithi '

a s omew a ar e r area th e e w s ma u a u ea . a R e na esse s h t d k , y llo pot ( c l l t ) ti l v l th e n a r n d i h r r e s re ar e a s ar er an t r ri e e o s e a . v i d k l ghtly l g th e a t e es . Scl tic ( cl ) r i a r f Reti n a (pa s Opt c eti nae) . PLATE 5 9

Vi ew of the interior of th e posterior half o f th e globe of the eye of a child

two years old.

is is th e same s e men as a re resen e o n PI. 8 wi s ffer Th p ci th t p t d 5 , th thi di — en ce th at th e preparation h as b een s ubj ected to th e i n fl uen c e o f fo rmali n fo r T r i i 8 ou rs and e n o o ra e . h e e n a s n ow a ue and th e r e ina 4 h th ph t g ph d t op q , t l

esse s are ess ear se en . Th e i is wi the rus o i u s in its v l l cl ly opt c d k, th po pt c en re is not so we e n e aroun we e r a rin o f i men t e s o s c t , ll d fi d ; d it, ho v , g p g d p t ,

th e or oi a r n is we s wn mme a e a o e it . Th e osi n th e ch i d l i g, ll ho i di t ly b v p tio of i s r u fove a centralis is marked by a rec ess w th puck ere d an d swo llen e dge o nd it.

i i a b i ru a ori r oi e . O s a a n . i i w o s us Ch o d (cho d ) ptic di k (p p ll opt c ), ith p optic i n th e cent re ; immediate ly above may be s ee n in dication s of th e ch o rioidal r n n ra w u r an d . c o ea e s e e d swo en re n a ar u n . Re i g F v c t li , ith p ck d ll ti o d it in al t ess e s . e r s era . R e in a ar v l Scle otic ( cl ) f t (p s optica) . PLATE 6 0

Vi ew of th e interior of th e posterior h alf of th e globe of th e right eye of an adu lt aft er fixing

Th e i is e is s een wi a we - mar e e a a n th e r e e o f Opt c d k ( ) th ll k d xc v tio , ight dg w t r w a a ro th e o m of th e o w r un th e hich h o s Sh d ow ac ss b tto h llo . A o d e dge th e re in a es se s ma b s en assin eir is ri u i n a u mm to th e t l v l y e e p g to th d t b t o bo t 4 . ou er or ef s i e of th e is th e ea en ra is is seen imme ia e sur t l t d d k fov c t l , d t ly round ed by a lighter zo ne ; there is al so a very fain t in dication of a lighter ann u ar - m n a 1 r m th ea . l zo e bout 5 m . f o e fov i a r i rioi ea c Re n a ar a . s ra b ori o . s Scle otic ( cle ) . Ch o d (ch d ) ti (p opt c ) d o ea en ra s su rr un e a i rin du e to th e en n of th e F v c t li , o d d by l ght g thick i g r etin a ; outsid e this th ere is a darker zon e boun ded by an oth er lighter ri n g a - i u 1 m i a f e is a n . wi m . m h e O i a s n ro t o ea . bo t 5 d t t f v pt c d k (p pill opt ci) , th a we - mar e e ress ion e a a a i ae n er i o er th e li of w ll k d d p ( xc v tio p p ll vi opt ci) , v p hich th e re in a e r n in u r R e in a esse s . t l vess l s a e seen ru n g o twa ds . f t l v l

PLATE 6 2

f r Vi ew of th e i nterior o t h e poste io r h alf of t h e gl obe of th e eye i n an a u t d l .

At c th e optic dis k i s seen with th e reti nal vess els radiating from it exten din g rom it in a wnwar ire i n an d t o th e r i s a t f do d d ct o , ight, hicken e d an d swollen f of re in a i n is a o u mm. from th e en re of th e o i s a i e it old t ; th , b t 4 c t pt c di k , l ttl p is se en : is mar s the osi on of th e ea en ra i Un un s . ort a e th th k p ti fov c t l f t ly, e s e men is n ot rre o rien e it h ad een th e fo w u n p ci co ctly t d if b , ld o ld have exte d e d

- ori n a o u war s r m th e is . is o th e so a e i a en ra is h zo t lly t d f o d k Th f ld, c ll d pl c c t l , is a er on s an fea ure in e es a are e amin e s me ime a er ea v y c t t t y th t x d o t ft d th .

The on ura i n of th e o is remar a a i e in all s u s e imens e ami n e c fig t o f ld k bly l k ch p c x d , an d would sugges t eith er a looser attachment of th e retin a i n this partic ul ar re on o r a e u re more rone t o th e a sor n u s gi t xt p b ptio of fl id .

n a b r s er i a R e a ars o . e a w th e r a a ti (p ptic ) Scl otic ( cl ), th cho ioid tt ch ed to i n n er u r a c O i s a a n er i i n t s i s f c e . pt c di k (p pill v optici) dication s of a c en tral e res s on w t a t en e u er li er w th e ret n a es s s ar d p i , i h hick d o t p ov hich i l v el e s een

- m r m a ass n . d a en ra s : a s e earan e wi th e a e p i g Plic c t li p o t o t pp c , th fove c ntrali s h in e ina e s R e s e s . close t o t e l ead l e . t l v l PLATE 6 3

View of th e i nterior of th e posterior h alf of th e globe of th e eye of a full - term

oe us . ame e e as a e 8 f t S y Pl t 3 .

Th e re in a a ears i an d es ere an d t ere more ar i u ar t pp th ck fl hy ; h h , p t c l ly i f h r n a in i is rown n o r m n n fo s In a n th e n e o t e e e s t e . th e lo g l ti l v , th i t p o i t ld c en tr e of th e i a i a i s s een th e e a a on o er th e e es of w i opt c p p ll (f ) xc v ti , v dg h ch h i e ma b se n i e n in u r r m t h e t e ret n al vess ls y e e pass ng . Ext d g pwa ds f o optic p apilla (h ad t h e specimen b een prop erly orien te d it wou ld have b een almost i n a u ar s is a ar r rm l r w o a e s see P s . ho zo t lly o t d ) thick f ld of ch ct i tic fo ( 3, 4 ,

th e a en ra s du e un ou e os - m r em an es o n s at th e plic c t li , d bt dly to p t o t ch g ; thi , in d i re ess th e a i u u mm fr m h n s a e en ra s s a e a . o t e e re p o t , c , fov c t l , it t d bo t 4 c t of T th e a a . h e esse s th e re n a are we s a e e th e e n s Optic p pill v l of ti ll di pl y d ( ) , v i s w n u er t an th e ar er ho i g p thick h t i es .

era b er i s . c o s swo a Scl ot c ( cl ) Ch orioid (ch orioidea) . Thick f ld of ll en

re n a rres on n th e re n s ome of th e ar er ein s . d ea ti , co p di g to di ctio of l g v Fov

n r h e sur a . e t a s o n t e th e a en ra s . e Re na esse s O c li , f c of plic c t li ti l v l f ptic i t r a a w e ess or e i n i re n a . p pill th op ic c xc avat o . g Th ck ti PLATE ' 6 4

i h os erior a of th e s er i View of th e i nter or of t e p t h lf cl ot c .

th e e th e e e a in een rem e th e s u ra Th e con tents of glob of y h v g b ov d, p rio r h as een orn rou o e er wi th e amin a us a a ert a n cho id al laye b t th gh , t g th th l f c c i m un i en er e from th e a er owe er rema ns in is is ou ne a o t of p gm t d iv d l tt , h v , i th tli d th e pos itio n an d dire ction of th e vari ous vesse l s an d n erves as th ey pass th rough

- t h e p eri cho rioidal s pace . Th e en tran ce of th e optic n erve is s een p as s in g th rough th e summit of

a n e e a ion Th e en ra ar er th e re na is s een w two m an on ge tl el v t . c t l t y of ti ith co p i e n v i s .

a Part of o n e of th e lo ng p os terio r ciliary arteri es torn ac ross an terio rly .

Th r s era s wn cu t r u . b On e th e iar n er es . c e s e of cil y v cl otic ( cl ) , ho th o gh d n ran e n e r e : wi n th e n er e in t h e en re ma be s een th e E t c of optic v thi v , c t , y n e n a es th e cen tral artery; to its right it s two compan ion ve i s are s een . I dic t th n r i s a Th e m res s n s impress ion of th e ramification s of e ve ae vo t co e . f i p io of On e th e en ae r i s ae er n th e th e s hort cili ary arteri es . g of v vo t co pi ci g s clerotic

ew th e sur a e th e s ero o ere w th e ro i s n ot A vi of f c of cl tic , c v d ith cho id , n u e as ws e n eres e e th e men a er th e re in a i cl d d , it Sho littl of i t t xc pt pig t l y of t r n its in rn a s ur a e cove i g te l f c .

PLATE 6 6

Vi ew of th e s cle ral s urface of a po rtion of th e ciliary body s ep arate d from its co n n exio ns this h as been dissected o ff from th e l e ft - h an d s id e of th e s peci 2 me n Sh own i n Pl ate 4 .

Th e an eri r mar in w ere th e ris h as ee n s e ara e r m its n n e n t o g , h i b p t d f o co xio w th e i ar rres n s th e an n u ar i amen see a es 2 an d ith c li y body, co po d to l l g t ( Pl t 4

n n n s er or th e u er s u rface th e r u us ar s is s een e Thi i g po t i ly, o t of o bic l cili i ( ) , i h i h e n a rs t r n wh lst to t e l e ft of th s t thi l ye of h e pars ciliari s retin ae (c) a e s how . Wh ere th e orbicul us joi ns th e ciliary body th e cili ary n erves may be s e en (a)

re a in u f rm a e us r u us an liosus th e res eri e r m b k g p to o pl x (o bic l g g ) , fib d v d f o i n er h s u s an e th e i iar o wh ch e t t e b t c of c l y b dy.

a i ar n e rea n u rm th e r i u u n li b era C li y erv s b ki g p to fo o b c l s ga g os us . Scl l i s ur a e ar r us are . c ars aris r i nae d n eri r f c of cili y body (co p cil ) P cili et . A t o e dge of cili ary body attached to th e an nu lar ligamen t at th e s clero - corne al u n n r m th e n n er s u r a e s mar n th e iris h a en rn a a j ctio ; f o i f c of thi gi s b e to w y. e ern a o r s era s ur a e of the r i u us i re Ext l cl l f c o b c l cil a . PLATE 6 7

iew of th e in n er re ina surfa e th e se ara e ri V ( t l) c of p t d cho oid .

Th e re in a h as e en e e e o ff r m is s ur a e e a n its n t b p l d f o th f c , l vi g pigme t laye r i n greater p art co n n ected with th e in n er surface of the chorioid an d cili ary O e r th e re a e r ar th e in n er s ur a e th e r i u u ar s t body. v g t p t of f c of o b c l s cili i hi s ‘ men a er h as een s ri e o ff as e re it we re m ore rea e a a e pig t l y b t pp d , if th dily d t ch bl

r m th e r Th e ris h as ee n rem e an d th e ree an eri r e e f o cho ioid . i b ov d , f t o dg of th e cili ary body corres pon ds to th e divid e d ann ul ar ligamen t at th e s cle ro rn ea m r n Th e ram a n s th e en ae r i s ae a r co l a gi . ific tio of v vo t co e s een th rough

- t h e thi n chorio capillary layer .

a vi e an nu ar ame n ame ntum an n u are w n n e s th e Di d d l lig t (lig l ), hich co ct cili ary body an te riorly with th e s cle r o - co rn e al ci rcumfe re n ce ; th e i ri s h as n s am e n b ar l r u be e t orn away from t h e i n n e r s id e of thi lig t . Cili y bod (co p s

are i n c ar r e s s es r es s us iares . d Or u us cili ) s e ction . Cili y p oc (p oc cil ) bic l ar s e O r u us ar s th e men te a e r th e ars ar s cili i . bic l cili i with pig d l y of p cili i re t n ae s r th a m n h e s rra i t ippe d o ff . f Co rres po n d s to e att ch e t of t o ra e ta ; r a ifi atio n s h e he e th e pigme n t s ee m s p articu larly thick . g R m c of t e ve n a

rt - h Th n n r r a s ae w n t r u th e r a ar a e r . e e s u e vo ico , Sho i g h o gh cho io c pill y l y i f c ' th e ch o rio i a r th r t a ta i Th e of d with mu ch of th e pigm e nt l ye of e e i n at ch ed . h r r o ea in s e t n cho ioid (cho i id ) c io .

I N D E"

Ir al an e e F Ne r 6 0 s e trat on an e . e s ar idi gl , il i gl v , cili y, 3 , 4 , 55 . Ir s 13 2 . ar e u s of 6 i , , 3 cili y pl x , 3 , 55 . o n n r fo f Ne r o u s tu n s ee R e i n e t s o . t a. c c ic ld , 33 v ic ,

on tra t on o s o f . c c i f ld , 35 r ts of c yp , 34 . ra a fo s o f di l ld , 33 . O t c u 21 8 p ic p , , 5 . struct ura fo s of S w a e . l ld ( ch lb ) , 35 s k . S ee O t a a di , 57 p ic p pill . n er e o u us of 8 v , c llic l , 5 .

a a 2 1 5 7 . p pill , , a a "u n s o o a cu of 21 8 . t re e sse s of . p pill , phy i l gic l p , , 5 h , c , 49 Ora s e rrata 1 20 23 , 9, , , 44, 55 . O r u u s ar s 8 1 0 1 2 6 4 1 bic l cili i , , , , 3 , , 1 5 , 55 L am na a s a s 1 1 . i b li , r rosa c ib , 7 , 53, 57 us a 8 c f c , , 4 , 53, 54 . ars ar s ret nae 1 1 1 . P cili i i , 9, 4 , 5 s u rach o ri o idalis 8 6 p , , 3 , 54 , 55 . r a re t nae 1 2 1 . i idic i , 9, 5 , 4 , 45

as u os a 1 1 . v c l , o t a ret n ae 1 1 . p ic i , 9, 4 , 44 , 55 t rea 1 1 vi , . ate ar fo s s a 26 1 . P ll , , 3 , 49 L e n s 25 8 4 5 4 , , 34, 3 , , 9 . e t nate ame nt 17 2 0 1 . P c i lig , , 3 , 4 , 4 a su e o f 1 c p l , 5 . m ran e 1 1 ee a ls e r or o a me . S o P ich i id l b , e uator a re on o f 2 q i l gi , 7 . S o m m ran up racho ri id al e b e . e u at or a o n e of 29 6 8 . q i l z , , 4 , 47 , 4 s a e 8 1 2 p c , : 4 ) 5 , 54° foet al 6 1 , 4 , 5 . c o f 8 6 8 1 e t t an a 1 2 . P i , l , 3, , 4 , 4 , 5 m e as u r m n s o f 2 e e t . , 7 Physiolo gical e xcavatio n o r cu p o f o ptic n u e r f a art o 2 . cl p , 7 a a 2 1 8 . p pill , , 5 p e ricap s u lar m e m ran e o f ( Re t b me n t a er o f re t na 1 25 6. Pig l y i , 9, , 54, 5 z iu s 6 ) , 4 . e u s an lio su s ar s 6 . Pl x g g cili i , 3 , 55 s tars 8 , 3 , 45 . a e n tra s o f re t n a 22 . Plic c li i , , 59 s u s tan t a ort a i s 2 b i c ic l , 7 . o ste r o r ame ra o f a u e o us h am e r P i c q c b , su s e n so r li ame n t o f 1 26 29 p y g , 3, , , 15 0 , 3 . 34, 49 4 7 S ee a ls o f . o n u e o 34 , 37 , , 49 Z l im t n m e m ran e o f o rn e a l i i g b c , n n a n d on u a ar s Zi Z l cili i . 1 7 . L ame nt an n u ar 1 3 2 g , 6 0 . i l , 7 , , 3 , 4 - os t le n t al a e 26 1 . P Sp c , , 3 e t n ate 1 2 0 1 p c i , 7 , 3 , 4 , 4 . ro ce s s s e ra 1 . P , cl l , 7 s u s e n s o r o f e n s 1 26 29 p y, l , 3, , , 34 , e ar ro r o e s s e s ar s e C ce s se s . P c , cili y, ili y p

4 7 . S ee a ls o o n u e o f n n 37 , , 49 l i . Z Z u i a r m ar n . P p ll y gi , 33 L m s a e e r o r o a y ph p c , p ich i id l , 53. 1 m e m rane . b , 5 m t st o a a . , 33

o n e o f r s on t ra t o n fo s o f . z i i , c c i ld , 35

a u a utea ret n a 2 1 M c l l of i , , 57, 59 . e m rana m tan s ar s 2 M b li i cili i , 5 . ’ em ran e D es e me t 1 s . R e es s e s o f "u n t . M b , c , 7 c h , 49 a o 22 0 4 8 2. R e t na 18 5 6 . hy l id , , 3 , 44 , , 49, 5 i , , 44 , e ri a s u ar o f R e t u s 6. fo e ta 2 60 . p c p l , zi , 4 l , 4, 45,

u ar 1 . 6 u n u s o u . p pill y, 5 f d c li, 5 s u ra or o a 1 1 0 1 m a ut ea 21 . . u a p ch i id l, , 4 , 4 , 53, 54 c l l , , 57 , 59 S ee a ls o L am n a su rach o rioi ali k 2 1 5 ic d s . o s ee ls O t 7 . S a o t i p p ic di , , p usc e ar 13 18 3 6 0 6 1 . a a . M l , cili y , , , , 37 , 4 , 55 , p pill I N DE"

i S o mata o f r s . R et na me nt a e r of 1 25 6 . t i , pig l y , 9, , 54, 5 i , 33 o f r a en tra s 22 . ar s . plic c li , , 59 cili y, i i , 34

f u ar o f r s . e n s o 8 . v i , 5 p pill y, i i , 33

S f S wa e . e ss e s of fo eta . tru tu ra o s o c v l l , 45 c l f ld h lb , 35

S ee als o Ma S u us r u ar s orn eae 9 1 6 0 . e ow ot . y ll Sp , 57 , 59 lc ci c l i c , , , 4 t n u 1 0 u a ute a . s e rae e e r s . c l l cl x , R 1 1 S ra h o r o a me mbranE H 0 1 et n ae ars ar s 1 . u i , p cili i , 9, 4 , 5 p c i id l , , 4 , 4 ,

ars r a 1 2 1 . p i idic , 9, 5 , 4 , 45 53, 54 ars o t a 1 1 S u s en s o r am e nt o f e n s 1 26 29 p p ic , 9, 4 44, 55 . p y lig l , 3, , , R n l o o f e t a es s e s 8 . . S ee a s o n u e i l v l , 5 34, 37 , 49 Z l

R tz us r n of 6 n n and onu a ar s . e e a s u ar m e m ra e . i , p ic p l b , 4 Zi Z l cili i

S U

S U ea t ra t 10 1 . emm an a o f 1 1 8 2 0 1 . chl , c l , 7 , , 3 , 4 , 4 v l c , , 4 , 55 S wa e o n tra t o n fo s of r s ch lb , c c i ld i i , 35 . fo s f r " s tru tu ra o s . c l ld i i , 35

S era 7 2 0 5 3 . 1 0 S ee a ls "as u ar c oat o f e e a . o cl , , 3 , 4 , c l y b ll ,

o rn t ur o f . ea a e r e U ea t ra t . c l p , 7 v l c o t foramen o f "o . "e n ae ort o sae s ee rt ose e n s . p ic , 7 , 53 v ic , ic v i k n f t c es s o . "t e o s u mou r 22 3 0 4 8 6 1 r u . hi , 7 i h , , , , S n n 2 e ra o u c t a . "r os e n s 8 1 1 6 1 6 o t e . cl l c j iv , 3 ic v i , 3 , 4 , 54, 5

ro ce s s 1 . p , 7 Y s u r 1 . p , 7

S - Ye low S Ot 2 1 5 9 S ee 013 0 acu a e ro o rn ea u n t o n e te rn a 1 0. cl c l j c i , x l , l P , , 57 , M l

utea . n te rna 10 0 . i l , , 4 l S e ot S Z r s ee c e ra . cl ic , l S a e r u m en t 1 0 1 2 f n n 1 a 1 4 7 8 . on u e o 26 29 37 6 4 7 p c , ci c l l , , , 34 , 4 , , 4 Z l Zi , 3, , , 34, , 4 , ,

o f Fo n tan a . . S ee a ls o S u s e n sor am ent , 34 49 p y lig

e r or o a 8 0 1 2 o f le n S . p ich i id l , , 4 , 4 , 5 , 54 .

o s t - l n al 1 e t 26 . on u a ar s see o nu e of n n p , , 3 Z l cili i , Z l Zi . O "F ORD : H ORACE H RT A A M . , . P RI NTER TO TH E U NI"ERS ITY