ASCARIDIA LINEATA, A PARASITE OF IN THE UNITED STATES1

By BENJAMIN SCHWARTZ Zoological Division, Bureau of Industry, United States Department of Agriculture INTRODUCTION male specimens from the , and, in common with specific diagnoses of a Heretofore it has been assumed that century ago, contains little that is of the large intestinal roundworm of diagnostic value. According to Dujar- chickens in the United States is As- din (3) A. perspicillum of Rudolphi is caridia perspicillum, a described apparently identical with Fusaria in- from the intestine of turkevs bv Rudol- flexa of Zeder. Dujardin {3) states that ph! in 1803 (leí).2 A recent study by the entries in the catalogue of the the present writer of specimens of Vienna Museum, whose helminthologi- Ascaridia collected at various times cal collections were studied by Rudolphi, from the intestine of chickens, in and contain no reference to A. inflexa from around Washington, D. C, in New chickens, this species being recorded Jersey, Kansas, and in several other only from ducks. Dujardin also states localities, has shown that the species that the catalogue in question contains in question does not conform to the but a single entry of A. perspicillum description of A. perspicillum as given from the turkey. by various writers, but conforms in Schneider (13), in his extensive mon- practically all respects to the descrip- ograph on , states that he tion of another species, namely, A. examined one male and one female linéala, which was described bv Schnei- specimen of Heterakis perspicillum and der in 1866 (13). found them to be identical with H. in- These two species have undoubtedly flexa, of which he also examined speci- been confused in the past, partly owing mens. In both cases the material ex- to their close relationship, and partly amined appears to have been material because the tendency of most workers studied by Rudolphi. Although who are not systematists is to make Schneider was unable to make out the host determinations of parasites. The structure of the lips in the specimens fact that A. perspicillum is an earlier labeled A scans perspicillum, he had no described species and that its type difficulty in making out the papillae locality is Europe is probably largely on the tail of the male, which he foiind responsible for the importance that has to correspond to those of A. inflexa. been assigned to it in textbooks on Since the papillae on the tail of the male parasitology, whereas A. lineata, which are commonly regarded as the most was originally described from Brazil, important specific characters in the has received but secondary considera- suckered roundworms (Heterakidae), tion in the widely used textbooks on it may be taken for granted that Schnei- parasitology, nearly all of which have der was correct in regarding A. perspi- been written by European workers. cillum and A. inflexa as identical. As will be presently shown, A. lineata is Schneider figures 9 pairs of papillae not only more prevalent then A. per- on the tail of the male of Heterakis in- spicillum in the United States and in all flexa (fig. 1), arranged as follows: 3 probability in other parts of the world, pairs of ventral papillae arranged in a but is also possibly the only species of row on each side of the sucker, the most Ascaridia parasitic in chickens in this cephalad papillae being anterior to, and country, the occurrence of A. perspicil- the third, or most caudal pair, being lum in American chickens not yet hav- posterior to the sucker, whereas the ing been definitely established. middle pair corresponds in position ap- proximately to the equator of the ASCARIDIA PERSPICILLUM (RU- sucker. The next group consists of 4 DOLPHI, 1803) pairs of papillae, of which 3 pairs are lateral and 1 pair is ventral, and finally, Rudolphi's description of ^.scan's there are 2 pairs of lateral papillae near perspicillum is based on immature fe- the tip of the tail.

1 Received for publication June 30,1924; issued June, 1925. 2 Reference is made by number (italic) to " Literature cited/ p.772.

Journal of Agricultural Research, Vol. XXX, No. 8 Washington, D. C. Apr. 15, 1925 Key No. A-89 (763) 764 Journal of Agricultural Research Vol. XXX, No. 8

Recently Ascaridia perspicillum has been figured by Bavlis and Daubney (1) (fig. 2) and by Smit (15) (fig. 3). According to the former, there are 10 pairs of papillae on the tail of the male, the first group consisting of 4 pairs of ventral papillae, instead of 3 pairs as figured by Schneider, the remaining FIG. 1.—Heterakis inflexa (after papillae agreeing as to number and Schneider, 1866) position with those of Schneider. The views expressed by Du jardin Smit, on the other hand, while agreeing (8) and Schneider (18) as regards the with Bavlis and Daubney as to the specific indentity of Áscaridia inflexa number of papillae, shows a somewhat and A. perspicillum have been generally different mode of arrangement, since accepted by helminthologists, includ- he figures 2 ventral and 3 lateral pairs ing Railliet (10), who states that this of papillae in the second group, as species has 10 pairs of papillae, but compared with 3 pairs of lateral and makes no statement as to their arrange- only 1 pair of ventral as figured by ment, excepting that 3 pairs are preanal Schneider and by Bavlis and Daubney. and 7 pairs are postanal. Railliet and The remaining papillae as figured by Henry (11), in their paper on the Smit correspond to those figured by classification of the Heterakidae, list Schneider. A. perspicillum as being possibly The different conceptions as to the identical with A. inflexa, a similar number and arrangement of the papil- attitude of uncertainty being expressed lae of Ascaridia perspicillum may be by Skrjabin (14). summarized as follows:

Schneider Baylis and Daubney Smit

Group 1 3 pairs of ventral papillae 4 pairs of ventral papillae 3 pairs of ventral papillae. Group 2 3 pairs of lateral papillae 3 pairs of lateral papillae 3 pairs of lateral papillae. 1 pair of ventral papillae 1 pair of ventral papillae 2 pairs of ventral papillae. Group 3. 2 pairs of lateral papillae 2 pairs of lateral papillae 2 pairs of lateral papillae.

number of ventral papillae in the an- terior two groups showing variations. Whether the species in question (As-

oö m m

FIG. 2.—Ascaridia perspicillum. (After Baylis and Daubney, 1922)

Assuming that Schneider, Baylis and Daubney, and Smit were dealing with the same species, it will be seen from the comparison of their descriptions of the papillae that they all agree as to the presence of only two lateral papillae FIG. 3.—Ascaridia perspicillum. (After Smit, in the region of the tip of the tail, the 1922) Api. is, 1925 Ascaridia linéala, a Parasite of Chickens 765

caridia perspicillum) is variable with ment of the papillae as figured by Von respect to the ventral papillae, or Linstow correspond accurately with whether under the name Ascaridia those of Schneider, although there are perspicillum two or more species have two discrepancies, namely, as regards been confused, must be left an open the elongation of the first ventral question. So far as concerns the papilla, which is figured as transversely arrangement of the papillae on the tail flattened by Von Linstow (fig. 5), of the male in specimens of Ascaridia whereas Schneider figures it as spherical from chickens in the United States and in shape. As regards the second from other localities that have been lateral papilla, Von Linstow figures it examined by the present writer, they do as directed laterally, whereas Schneider not correspond to any of the patterns figures it as directed ventrally. described for A. perspicillum, but agree with that of another species, namely, A. lineata. ASCARIDIA LINEATA (SCHNEIDER, 1866) Schneider (13) describes Heterakis lineata from the intestine of the from Brazil in the same paper in which he discusses the identity of Heterakis perspicillum and H. inflexa. Schneider differentiates //. inflexa (H. perspicil- lum) from H. lineata on the basis of the structure of the lips as well as on the basis of the number of papillae on the tail of the male. He states that H. inflexa has 3 dentigerous ridges on each lip, the first 2 being round and the FIG. 5.—Heterakis lineata (after Von Linstow, 1883) third (most posterior) being quad- rangular, whereas H. lineata, according Von Linstow (8) records Heterakis to this writer, has only 2 dentigerous inflexa from the chicken, but from ridges, the second ridge being very his description of the papillae, in which small. As far as concerns the papillae 3 pairs are enumerated in the region on the tail of the male, Schneider of the tip of the tail, 2 being lateral figures 10 papillae for H. lineata and 1 ventral, it may be taken for (fig. 4), the last group of papillae in the granted that he was dealing with region of the tip of the tail consisting Ascaridia lineata. of 3 pairs, 2 lateral and 1 ventral, as Wolffhügel (18) records Heterakis compared with only 2 pairs of lateral lineata from Switzerland from the papillae in H. inflexa. The remaining chicken and the duck, but he records papillae, according to Schneider's fig- H. inflexa (Ascaridia perspicillum) ure, correspond in number and posi- only from the grouse (Tetrao urogallus). tion to those of H. inflexa. Travassos (16) records and figures Ascaridia lineata from chickens in Brazil, the type locality of this species. His drawing of the tail of the male (fig. 6) shows a perfect agreement with that of Von Linstow (fig. 5) as to number, arrangement, and . direction of the papillae.

FIG. 4.—Heterakis lineata (after Schneider, 1866) Other records of the occurrence of Ascaridia lineata besides those given by the present writer are as follows: Von Linstow (7) records and figures Heterakis lineata from the duck from Turkestan. The number and arrange- FIG. 6.—Ascaridia lineata (after Travassos, 1913) 19978—25t G 766 Journal of Agricultural Research Vol. XXX, No. 8

Gedoelst (4) records Ascaridia lineata obviously ventral in position. The from the chicken in the Belgian Congo. description that Magalhäes gives of Boulenger (#) records and figures H. brasiliensis is too incomplete to Ascaridia lineata from the chicken permit any definite opinion as regards in Zanzibar on the basis of a single male the status of that species. specimen. His figure (fig. 7) agrees In all of the records of the occurrence in all respects except one with that of of Ascaridia lineata which have just Von Linstow and Travassos, the been reviewed, excepting that of exception being the direction of the Schneider, no mention is made of second lateral papilla, which is de- A. perspicillum as a parasite occurring scribed as being turned ventrally, thus alone or in association with A. lineata agreeing in this respect with Schneider's in the same host species. This fact is figure. Boulenger observes that these of importance and indicates that when discrepancies are probably due to specimens of Ascaridia from chickens individual variations. and related domestic have been According to Boulenger (2) Ascaridia actually studied morphologically they hamia, a species described by Lane have been found to be A. lineata, (5) from the intestine of chickens in which is apparently the common Bengal, India, is Ascaridia lineata, species of Ascaridia in domestic birds. a view with which the present writer is in full agreement. Lane's figure and

o-i mm 0-2/77/n FIG. ! -Ascaridia hamia (after Lane, 1914) FIG. 7.—Ascaridia lineata (after Boulenger, 1923) description of the papillae (fig. 8) show OBSERVATIONS ON ASCARIDIA a perfect agreement with those of LINEATA BY PRESENT WRITER Schneider, Von Linstow, Travassos, and Boulenger, and although his Observations on Ascaridia lineata by description of the species as a whole the present writer were made on shows some discrepancies as compared material collected in the United States with the present writer's observations by various workers in this laboratory on A. lineata, these discrepancies can in the vicinity of Washington, D. C, all be accounted for, as will be presently as well as on material forwarded to shown, on the basis of individual this bureau for determination from variation. several different localities. In addition According to Travassos (16), Hete- to American material, specimens col- rakis brasiliensis Magalhäes, 1892 lected from chickens in the Philippine (9), is also a synonym of Ascaridia Islands and at Tonkin, Indo-China, lineata. Magalhäes' description is were also studied. In material for- rather vague as regards the papillae warded from Indo-China immature on the tail of the male and does not specimens of A. lineata from the goose agree with his figure in all respects. (fig. 9) were identified, this host being He states that the worm has 9 pairs of new for this species of parasite. lateral papillae, but he actually enu- In all specimens that have been merates 10 pairs and one accessory examined, the number and arrange- papilla. Certain of the papillae re- ment of the papillae on the tail of the ferred to by Magalhäes as lateral are male correspond to those described by Apr. 15, 1925 Ascaridia lineata, a Parasite of Chicle ens 767 various workers for Ascaridia lineata. VARIATIONS IN ASCARIDIA LINEATA The different variations as regards the first ventral and second lateral papillae HEAD.—The head varies in size cor- which have been referred to elsewhere responding to different sized specimens. in this paper were also encountered. The two subventral lips are practically The number of papillae on the tail of equal in size, wrhile the dorsal lip is the male was found to be 10, the first somewhat larger. As has already been stated, Schneider (13) described two dentigerous ridges, the second one, ac- cording to this wwker, being very small. Lane (5) refers to only one ridge which

FIG. 10.—Ascaridia lineata (original) from the chicken, an., anus; s., sucker; sp., spicules he states has the appearance of a wavy i/iomm. line when viewed from certain aspects. The present writer observed a rather FIG, 9.—Ascaridia lineata (original) from the goose. prominent dentigerous ridge, contain- an., anus; s., sucker; sp., spicules ing distinct teeth, but failed to make out a second smaller dental plate re- group consisting of 3 pairs (ventral) ferred to by Schneider. Each lip bears arranged in a linear series on each two papillae, these having been also side of the sucker, the second group observed by Lane (5). No interlabia consisting of 4 pairs (3 lateral and 1 are present. ventral), and the last group consisting OESOPHAGUS.—In adult specimens of 3 pairs (2 lateral and 1 ventral), the oesophagus is 3 mm. to 4 mm. long, (figs. 10, 11, 12, 13.) club shaped, and about 0.35 mm. in 768 Journal of Agricultural Research Vol. XXX, No. 8 maximum width. In immature speci- flattened, although in one immature mens the oesophagus is relatively specimen from the goose it was spherical shorter and narrower (fig. 14), various in shape (fig. 9). With regard to the gradations in length and width, de- second lateral papilla, it was observed pending upon the size of different speci- to be directed laterally in all specimens mens having been observed. examined, save in one immature form PAPILLAE.—While the number of from the goose, in which the papilla papillae in the male of Ascaridia lineata was directed ventrally (fig. 9). is constant, the positions of the indi- Other variations with regard to the papillae are as follows: The last two lateral papillae were found to be very close together in certain specimens and comparatively distant from each other in other specimens. In the middle group of papillae the three lateral papillae were found to be equidistant in some specimens, whereas in other

i/iomm

FIG. 11 —Ascaridia lineata (original) from the chicken

i/iomm

FIG. 13.—Ascaridia lineata (original) from the chicken, x., tip of spicule specimens the two anterior papillae of this group were close together and the most posterior papilla relatively dis- tant from the middle papilla. The FIG. 12.—Ascaridia lineata (original) from the lateral papillae also show considerable chicken variation in size, relatively large papil- lae occurring in mature specimens and vidual papillae with respect to one smaller papillae in very young speci- another and the direction of the first mens. The ventral papillae afford the ventral and second lateral papillae are same degree of variation as regards rather variable (figs. 4 to 13). It has location, shape, and size, the latter already been pointed out that certain variation being correlated with age. writers describe the first ventral papilla The first ventral papilla is considerably as lying in a transverse direction (figs. anterior to the sucker in certain speci- 5, 6, and 7), whereas other observers, mens, whereas in others it is on a level including Lane (6), have figured it as with or somewhat anterior to the spherical (figs. 4 and 8). The present cephalad border of the sucker. The writer found that in most cases the fourth ventral papilla is fairly constant first ventral papilla is transversely in position, somewhat posterior to the Apr. is, 1925 Ascaridio, linéala, a Parasite of Chickens 769 second lateral papilla, but the location from 0.53 to 0.57 mm. in length. Some- of the last ventral papilla is rather what larger specimens from chickens variable, being anterior to the last had spicules measuring from 0.7 to 0.8 lateral papilla in certain specimens and mm. Spicules from not quite fully posterior to it in other specimens. Not grown specimens from chickens in the infrequently the arrangement of the Philippines varied from 0.9 to 1.3 mm. papillae on the two sides of the bursa in length. Mature specimens from is asymmetrical (fig. 8). The position chickens from Tonkin showed a varia- of the first lateral papilla with respect tion in the length of the spicules from to the anus is also somewhat variable, 1.6 to 2.4 mm. Specimens from the being located either slightly anterior United States showed a similar varia- to, on a level with, or rarely somewhat tion in the size of the spicules, the posterior to the anus (figs. 4 to 13). youngest immature forms measured having spicules 0.6 mm. long, whereas large mature forms had spicules some- what in excess of 2 mm. In view of the specific importance that is commonly attributed to the size of the spicules in nematodes, the rather wide range of size variation noted in this species is worthy of emphasis. SUCKER.—The size of the sucker as given by Lane is 0.2 mm. in diameter, agreeing closely with that of Travassos and Boulenger (so far as can be judged from the latter's figure for which a scale is given). The maximum diam- eter of the sucker as observed by the present writer was 0.25 mm. and the minimum diameter in very young speci- mens was somewhat less than Oil 4 mm Additional variations were observed as regards the distance of the nerve ring and excretory pore from the cepha- lic extremity, the length of that portion of the vagina that extends cephalad, and the length of the tail in both sexes. The most conspicuous of these varia- tions are given below: According to Lane (5), the vagina runs cephalad for a distance of about 1 mm. before it turns caudad. In very young forms the writer found that the vagina runs cephalad for a distance of only 475 M (fig. 15), while in somewhat larger speci- mens that distance was found to be 670 fi. In mature specimens the cepha- lad portion of the vagina was found to be somewhat longer than that given by Lane. The tail of the male in fully grown specimens was found to be 0.7 mm., as compared with 0.5 mm. given Fig. 14.—Anteria end of Ascaridia lineata (original). by Lane, with a decrease in size in e. p., excretory pore; n.r., nerve ring; oes., oe- sophagus. smaller specimens. The distances of the excretory pore and nerve ring from SPICULES.—A considerable range of the cephalic extremity were found to be variation exists as regards the length somewhat greater than those given by of the spicules in Ascaridia lineata. Lane in fully grown specimens, but con- According to Travassos (16), the spic- siderably shorter in immature speci- ules are 1.4 mm. long. According to mens (fig. 14). Lane (5), they are 2 mm. long. Von The position of the vulva is near the Linstow (8) states that the spicules of equator according to Lane (5), which Heterakis inflexa (misidentification of corresponds to the observations of the Ascaridia lineata) are 1.9 mm. long. present writer. According to Travas- Immature specimens from the chicken sos (16) it is in the first third of the and goose from Tonkin, 1.8 mm. long, body. The size of the , which are showed a range in spicule variation thick shelled, the shell being smooth, is 770 Journal of Agricultural Research Vol. XXX, No. about 80 by 50 M according to observa- the sucker; a second group consisting of 3 pairs of lateral and 1 pair of ventral papillae, all being post- tions of the present writer (fig. 16), anal in position with occasional variations in which which is in agreement with the size the first lateral papilla may be on a level with or given by Travassos but is larger than somewhat anterior to the anus; a third group of 2 pairs of lateral and 1 pair of ventral papillae in that given by Lane (65 X 40 M) • Since the region of the tip of the tail. Spicules, variable practically all of Lane's measurements in size, minimum length 0.54 mm. in young forms fall short of the present writer's meas- and maximum length 2.4 mm. in adult forms; pro- vided with sheaths. Spicules terminate in a rather urements, it may be concluded that no prominent rounded enlargement (fig. 17). The such actual discrepancy as regards the sucker is circular, variable in size, measuring from size of the eggs which Lane's figures 0.2 to 0.25 mm. in adult specimens; considerably smaller in immature forms. The length of the tail, indicate really exists, the difference be- which ends in a slender tip in adult forms, is from ing due in all probability to some slight 0.5 to 0.7 mm. fault in the calculation of measure ments.

FIG. 17.—Tip of spicule of Ascaridia lineata viewed from different aspects (original)

FEMALE.—The vulva lies approximately at the middle of the body. Eggs thick-shelled, elliptical in shape, 80 ¿i long by 50 M wide. Anus from 1.1 to 1.3 mm. from tip to tail in adult forms and shorter in immature forms. Tail ends in a slender tip (fig. 18). HOSTS.—Gallus domesticus, Anas boschas domes- ticus, and Anser domesticus. LOCALITIES.—Europe, North and South America, Asia, and Africa. (tomín. THE GENUS ASCARIDIA DUJARDIN, FIG. 15.—Vulva and vagina of Ascaridia lineata (original), v., vulva; vag. vagina 1845 Railliet and Henry (11) define the genus Ascaridia as follows: Mouth with three lips; esophagus without a bulb, often with lateral membranes. Caudal alae of male feebly developed. Spicules equal or subequal, without an accessory piece. Preanal sucker rounded, with chitinous ring; papillae relatively large. Vulva toward the middle papillae of the body; uteri opposed; eggs thick-shelled. In a paper on suckered roundworms, Fig. 16.—Eggs of Ascaridia lineata (original) Lane (¿) amends the diagnosis of the genus Ascaridia as given by Railliet SPECIFIC DIAGNOSIS OF ASCARIDIA LIN- and Henry, by adding the following EATA SCHNEIDER, 1866 generic characters: 10 pairs of caudal papillae in the male, and similar spic- Synonyms.—Heterakis perspicillum Von Linstow, 1894 (misdetermination); Ascaridia hamia Lane, ules. In a later paper Lane (6) dis- 1914; H. braziliensis Magalhâes, 1892 (according to cusses the generic diagnosis of Ascari- Travassos, 1913). dia in greater detail, insisting on the Mature specimens 70 to 120 mm. long by about 1 mm. or more wide, the females being larger than view that species having more than the males. Lips prominent, each lip provided with 10 pairs of papillae that are now two papillae and a dentigerous ridge bearing distinct assigned to the genus Ascaridia should teeth. Oesophagus simple, from 3 to 4 mm. long by 0.34 mm. wide in adult specimens. The nerve be placed in another genus, but he ring is located approximately anterior to the first makes no further reference to similar- fourth of the oesophagus and the excretory pore is ity in size of spicules. According to posterior to the nerve ring. MALE.—Ten pairs of papillae arranged in 3 Travassos (16), the male of Ascaridia groups, as follows: An anterior group of 3 pairs of columbae has 14 pairs of papillae; ventral papillae arranged on each side of the sucker, that of A. trúncala, the type species the middle pair of this group of papillae being along- side, the anterior pair being on the level with or of the genus, 15 pairs, and that of anterior to, and the posterior pair being posterior to A. magalhaesi 12 pairs. In addition Apr. is, 1925 Ascavidia lineata, a Parasite of Chickens 771

to the forms just mentioned, there are One point on which Lane and Travas- several species of Ascaridia that have sos agree, however, is the importance of more than 10 pairs of papillae in the the structure of the oesophagus in the male. So far as concerns A. trúncala classification of suckered roundworms. of Travassos, Lane considers it con- Lane (6), referring to the members of generic with Gireterakis girardi, a the genus Ascaridia, states that they new genus and new species having will probably be subdivided in the a bulbed oesophagus, described by future into several genera and will himself, and he therefore concludes come to occupy the status of a sub- that A. trúncala of Travassos is not family at least, and that the genera Heterakis, Ganguleterakis, Gireterakis, and related forms having a bulbed oesophagus will constitute another sub- family. Future investigation may per- haps justify Lane's position, but'there appears to be no need at the present time to limit the definition of the genus Ascaridia beyond what is given by Railliet and Henry (11).

SYSTEMATIC POSITION OF ASCA- RIDIA LINEATA

In common with other species of the genus, Ascaridia lineata is generally re- ferred to the family Heterakidae, which is included in the superfamily Ascaroidea. According to Travassos (17), whose conception of the superfamilies is to some extent at 00 mm variance with that of Railliet and others, the genus Ascaridia belongs to the FIG. 18.—Tail of female of Ascaridialineata (original) family Ascaridae, and not to the family Heterakidae, which he limits to forms identical with Fusaria trúncala of having a bulbous oesophagus. Travas- Zeder, the type species of the genus sos furthermore assigns the family Ascaridia. Lane has assumed that Heterakidae to the superfamily Oxy- the species described by Travassos as uroidea, thus placing the genus As- A. trúncala possesses a bulbous oesoph- caridia in a different superfamily, agus and therefore does not belong namely, Ascaroidea. This conception to the genus Ascaridia. In the writer's of the affinities of the genus Ascaridia opinion this assumption is unwarranted. differs radically from that of Railliet In the absence of definite information and Henry (11), who place Ascaridia to the contrary it seems fairer to with other suckered roundworms in the assume that the species designated by family Heterakidae. The genus As- Travassos as A. trúncala has a simple caridia has undoubted affinities with oesophagus characteristic of the genus certain Ascaridae so far as concerns the Ascaridia, a fact which is clearly im- structure of the oesophagus and the plied in the generic diagnosis of presence of dentigerous ridges on the Ascaridia as given by Travassos. Lane's lips, but so far as concerns the presence additional assumption that A. truncatu of a preanal sucker and a bursalike of Travassos included more than one tail in the male, it is closely related to form must be left open to question the Heterakidae. in the absence of definite information The zoological position of the genus on this point. The point to be con- Ascaridia is a question that can not be sidered in this connection is that finally settled until careful morpholog- A. trúncala of Travassos is a parasite ical comparisons are made not only of of birds, whereas Gireterakis girardi is the adult forms, but also of the larvae a mammalian parasite, the difference at various stages of development, with in host relationship of the two forms those of corresponding stages of genera favoring the probability of their being of Ascaridae on the one hand and with different genera. genera of Heterakidae on the other. 772 Journal of Agricultural Research Vol. XXX, No. 8

SUMMARY AND CONCLUSIONS (2) BOULENGER, C. L. 1923. A COLLECTION OF NEMATODE PARASITES FROM ZANZIBAR. Parasitology 15: 113-121, The principal facts presented in the illus. foregoing pages may be summarized as (3) DUJARDIN, F. follows: 1845. HISTOIRE NATURELLE DES HELMINTHES OU VERS INTESTINAUX. 654 p., illus. Paris. Ascaridia lineata is the common in- (4) GEDOELST, L. testinal- roundworm of chickens in the 1916. NOTES SUR LA FAUNE PARASITAIRE DU CONGO BELGE. Rev. Zool. Africaine 5: 1-90, United States, the occurrence of A. illus. perspicillum in this country not having (5) LANE, C. as yet been established on the basis of 1914. SUCKERED ROUND-WORMS FROM INDIA AND morphological comparisons of Ascaridia CEYLON. Indian Jour. Med. Research 2: 655- occurring in American chickens with the 669, illus. (6) — different forms that have been de- 1917. GIRETERAKIS GIRARDI (N. G., N. SP.) AND scribed as A. perspicillum. OTHER SUCKERED NEMATODES. Indian Jour. So far as can be judged from the Med. Research 4: 754-765, illus. various illustrations of Ascaridia per- (7) LINSTOW, 0. F. B. VON 1883. NEMATODEN, TREMATODEN UND ACANTHO- spicillum, this species is either highly CEPHALEN, GESAMMELT VON PROF. FEDT- variable as regards the arrangement SCHENKO IN TURKESTAN. Arch. Naturgesch. and location of the papillae in the tail 49 (1): 274-314, illus. (8) of the male, or else several different 1884. BERICHT ÜBER DIE LEISTUNGEN IN DER species have been confused under one NATURGESCHICHTE DER EINGEWEIDEWÜRMER name. IM JAHRE 1884. Arch. Naturgesch. 50 (2) : Ascaridia lineata exhibits considera- 711-745. (9) MAGALHäES, P. S. DE able individual variations, these being 1892. NOTES D'HELMINTHOLOGIE BRéSILIENNE, correlated with size and therefore with (DEUXIèME NOTE). Bul. Soc. Zool. France 17: age of the different specimens. Of 219-221, illus. special interest in this connection is the (10) RAILLIET, A. 1895. TRAITÉ DE ZOOLOGIE MÉDICALE ET AGRI- variation in the length of the spicules, COLE. Éd. 2, [fase. 2], p. 737-1303, illus. Paris. organs to which considerable specific (11) and HENRY, A. importance is usually assigned by 1914. ESSAI DE CLASSIFICATION DES "HETERAKI- DAE". Cong. Internat. Zool. (1913) 9: 674-682. helminthologists. Of perhaps equal (12) RUDOLPHI, K. A. importance is the variation in the size 1803. NEUE BEOBACHTUNGEN ÜBER DIE EINGE- of the sucker, which has a chitinized WEIDEWÜRMER. Arch. Zool. und Zoot. 3 (2): 1-32. rim. (13) SCHNEIDER, A. Ascaridia lineata is recorded for the 1866. MONOGRAPHIE DER NEMATODEN. 357 p., first time as a parasite of the goose, on illus. ^Berlin. (14) SKRIABIN, K. I. (SKRJABIN, K. J.) the basis of specimens from Indo- 1916. NEMATODES DES OISEAUX DU TURKESTAN China. RUSSE. Ann. Mus. Zool. Acad. Imp. Sei. In view of the apparent absence of Petrograd (1915) 20: 457-557, illus. (15) SMIT, H. J. Ascaridia perspicillum from American 1922. PARASITOLOGISCHE STUDIEN IN NIEDER- chickens, various facts published in the LäNDISCH-INDIEN. Deut. Tierärztl. Wchnschr. United States concerning the life his- 30: 506-512, 526-531, 546-548, illus. tory, pathology, and physiology of (16) TRAVASSOS, L. 1913. SOBRE AS ESPECIES BRAZILEIRAS DA SUB- A. perspicillum as well as facts per- FAMILIA HETERAKINAE RAILLIET & HENRY. taining to medicinal treatment in all Mem. Inst. Oswaldo Cruz 5: 271-318, illus. probability refer to Ascaridia lineata. [German text, p. 271-318.] (17) 1920. ESBOÇO DE UMA CHAVE GERAL DOS NEMA- LITERATURE CITED TODES PARáSITOS. Rev. Vet. e Zootech. 10: 59-70. (1) BAYLIS, H. A., and DAUBNEY, R. (18) WOLFFHÜGEL, K. 1922. REPORT ON THE PARASITIC NEMATODES IN 1900. BEITRAG ZUR KENNTNIS DER VOGELHEL- THE COLLECTION OF THE ZOOLOGICAL SURVEY OF MINTHEN. 204 p., illus. Freiburg i. Br. INDIA. Mem. Indian Mus. 7: 263-347, Mus. (Inaug. Diss., Univ. Basel.)