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Home , Brindle, Fawn (colour), Piebald

THE INHERITANCE OF COAT IN GREAT DANES C. C. LITTLE AND E. E. JONES Station for Experimental Evolution, Carnegie Institution of Washington, Cold Spring Harbor, Long Island, AT. Y.

I. HISTORICAL OUTLINE (b) Color Varieties of the Breed.— (a) Description of the Breed.—The Stonhenge (loc. cit.) records the recog- Great Dane is known to all dog breeders nized of this breed as follows: "The color resembles that of the mas- •as one of the most vigorous of the large tiff, being brindled or fawn, but some- breeds. Its origin is somewhat in times of a bluish slate with blotches of doubt. Stonhenge (1873), in describing ." That several additional colors the breed, notes its frequent description appeared and were recognized within a under the name of Boar Hound and relatively short time is evident from states that it ... "does not appear the description of the orthodox colors to be a distinct breed, but rather a given by Leighton, (loc. cit.) These compound of the greyhound, the mas- are, according to his statement, , tiff, and the terrier." On the other fawn, , black, and harlequin. In hand, Leighton (1907) believes that the the brindle dogs the ground color may antiquity of the breed is established be any shade from light to dark by the fact that representatives of a -yellow, .on which the brindle ap- type sufficiently similar to be' consid- pears in darker stripes. The harlequin ered its ancestors are found on early should have, on a pure white ground, Egyptian monuments. Its more recent' fairly large black patches which must history appears to focus mostly on be of irregular shape, broken up as if Germany, where it has been given the they were torn. The standard of the title of "Deutsche Dogge." For a breed also states that, in harlequins, long time it was, in all probability, fawn and brindle shades are undesirable. crossed, with other breeds of large To reduce these color varieties to a German dogs such as the Hatzrude, simpler basis from a genetic point of which is a medium-sized dog about view they may be listM as follows: intermediate in appearance between the Black (Fig. 12, No. 3); blue (dilute heavy and thickset "dogge" type of black) (Fig. 12, No. 6); harlequin the and the slimmer and less (black and white), (Fig. 12, No. 2); powerful "hund" type. Other some- brindle (Fig. 12, No. 4)—various shades what similar varieties with which it including a dilute or "blue" brindle may have been crossed are the Sau- (Fig. 12, No. 7); fawn (Fig. 12, No. 5) fanger, Ulmer Dogge, and Rottweiler —various shades including a dilute Metzerghund. light, or "dove" fawn (Fig. 12, No. 8). But whether the Great Dane be The fawn is with dark-brown considered as one of the oldest breeds or black muzzle and feet. The dilute or not really has little influence, from fawn has a dull, faded silvery appear- the viewpoint of the present investiga- ance, quite well known to those who tion. It is sufficient that for a period have seen such color varieties of rodents of at least fifty years they have been as dilute brown mice or dilute recognized and selected with as great rabbits. Fawn is, moreover, easily care as have the other breeds of thor- distinguishable from the yellow of oughbred dogs. Their color varieties pointers which is a clear, yellow-orange are distinct and are well established as or lemon color, not nearly as rich or follows: heavy in shade as the more brownish 309 310 The Journal of Heredity pigmentation of the fawn. The blue heritance in pointers and has reportep is a true dilute type,'- apparently directly ' the existence of certain alternative color analogous to the maltese cat and the ' types referable to Mendelizing factors. '•'"dilute black" mouse or rabbit.' One of these, the factor for black pig- vary considerably in depth ment, the hypostatic form of which pro- of color. They may. have a rich, . duces brown pigment, had been observed golden grpund cqlpr .or. a duller and previously by Lang, .1910, in a single darker brown. The pattern which ap- cross which he made. This mutation pears on this ground color is an ir- from.large B to small b does not appear regular streaking with black. It is. to have occurred in Great Danes in so variously . described- as brindled, far as the records studied are con- streaked, striped,' or tigered. The rel- cerned. One dog was described as ative amount of black 'and yellowish- "'.' in color, but inasmuch as blue brown pigment in the coat varies con- commonly approaches "liver" in ap- siderably, some brindles being almost pearance and, further, inasmuch as this entirely fawn, "with a trace of black, dog occurred in a mating where and others-being predominantly, if not would be expected, the dog in question entirely, black, in appearance. ' Some has been classed as blue. The second evidence that brindles may rarely be factor to be recognized in pointers is entirely black in appearance or, at the the factor E for the extension of black other extreme, fawn, will be presented and brown pigment in the coat. In when, the detailed -color crosses are the hypostatic form of this factor the considered. colored portions of the coat are orange or lemon-yellow. Whether the yellow Dilute brindles have a dull, silvery of pointers is identical with, of com- type of coloration, affecting both the parable to, the fawn type of Great .ground pigment and the dark striping Danes is doubtful. It represents a and giving an appearance easily dis- distinctly yellow type in which "there tinguishable from the light but in- is no marked darkening of the muzzle tensely pigmented brindles. The dif- or the extremities such as one finds in ference is. qualitatively almost exactly fawn Great Danes. Until further care- that recognized irt other mammals and ful experimentation is made, 'therefore, described by one of the writers in the we shall have to recognize four distinct case of yellow mice (Little, 1911). and possibly genetically different types Spotted- forms are of two sorts, of red-yellow coat pigmentation in harlequins already described, and dogs dogs: First, the orange or lemon- on which small white spots occur on yellow of pointers and English setters; the chests or.feet. (Fig. 12, No.' 1.) second, the brownish-yellow of most Harlequin i§ a pattern producing, on the "red" dachsunds, and possibly of Irish one hand, a pure white animal with a terriers; third, the dark, muzzled fawn dark "nose, and on the other hand an of ," greyhounds, and Great animal with a very small' amount of Danes; and finally, the almost white. Individuals of the latter sort red of Irish setters. The genetic re- might possibly be confused with animals lationships of these four types would possessing spotting of the second (non.- make a most interesting study. harlequin) type. Animals with the second type of spotting are not con- In 1915, Barrows and Phillips found sidered desirable specimens, and are in that the B and E factors were both Great Danes, as in other breeds, vigor- present in cocker spaniels, . and in ously selected against. The effects of addition discovered indications of a this upon their occurrence and descrip- dilution factor producing dilute black tion will be considered later. or blue individuals and also, in the (c) Review of Previous Literature.— yellow series, cream or white. On One of the writers (Little 1914) has used page - 393 they state that dilute . %he American Kennel Club Stud Books are cream in color. Whether, however, for- the purposes of studying color in- dilute reds might not also be dull COLOR VARIETIES IN THE GREAT DANE In this breed of dogs several color varieties are distinct and well established. "To reduce these color varieties to a simpler basis from a genetic point of view they may be listed as follows: Black (No. 3 above), blue (dilute black, No. 6), harlequin (black and white, No. 2), brindle—various shades including a dilute or 'blue' brindle (No. 7), fawn—various shades including a dilute light, or 'dove' fawn (No. 8). (Fig. 12.) 312 The Journal of Heredity- faded yellow in color does not appear factor for spotting which he to have been considered. From analogy considers at the present time un- with all the forms previously worked analyzed. He also mentions the inter- on, in which a dilution factor of the esting experiments of Pearson, Nettle- type apparently existing in cocker ship, and Usher, resulting in the isola- spaniels has been established, one would tion of a factor for partial in expect that such would be the case. Pekinese. With this brief review we What we believe to be conclusive may now turn to a consideration of the evidence of a dilution factor in Great observed facts. Danes will be considered later. The evidence on the inheritance of II. OBSERVED EXPERIMENTAL RESULTS spotting obtained by Barrows and The following matings have been Phillips is extremely interesting, for it recorded from data derived from the apparently demonstrates that there are American Kennel Club Stud Books, at least two types of spotting. Thus Volumes 11 to 34 inclusive. As was spotted by spotted matings produced the case in pointers, numbers before two hundred and twenty spotted and Volume 11 represented data collected fourteen solid colored individuals. The at a time and under circumstances not spotted parents in these cases were well adapted to accuracy, and con- apparently the ordinary parti-colored tained only a small number of available cockers in which considerable white is animals. The strong and weak points always present. When solid pigmented in data collected from stud books have animals were crossed together, nineteen already been touched upon in an earlier solid colored individuals were produced, paper by one of us already referred to and in addition two pups from a single (Little, 1914), and need not be further litter showed very small white spots on considered at present. the breasts. We shall see later that Inasmuch as many types of matings these conditions are paralleled closely have been involved, it will be convenient in Great Danes. to analyze them in groups according to Wright, 1918, in reviewing color the particular factor or factors which we inheritance in mammals, recognizes in believe they possess. dogs the existence of the B and E factors and of the dominant spotting which he III. THEORETICAL INTERPRETATION calls R, or . Just how far this roan A breed of dogs such as Great Danes factor is similar to the fine mixtures of may biologically be considered as a pigment found in the roans of mixed population. In so far as any and is uncertain. It seems quite one pair of allelomorphs are concerned possible that in short-haired dogs such there will be individuals of three sorts: as Great Danes or coach-dogs, a type DD, DR, and RR. If there has been of color distribution which in the long- no particular degree of inbreeding or haired breeds such as English setters selection, they will probably be present produces a mixture of indistinct spots in approximately the proportion of one and regions of apparent "roaning," DD, to two DR, to one RR. Con- might produce clear, well-defined spots. sidering for a moment only the D in- The possible danger of considering the dividuals we find that in proportion to dominant spotting found in cocker the degree of inbreeding and selection, spaniels a true roan is seen in such the relative number of DD individuals varieties of dogs as the "tigered" or becomes greater, and we might therefore "dappled" dachsund. Here there ap- expect some populations to show among pears to be a real intermixture of black, their D animals a ratio of one DD to sparsely pigmented, and almost, if not one DR, or perhaps two DD to one DR. entirely unpigmented hairs; a condition For a population in which DD and which more closely resembles the roans DR animals are present in these different which have hitherto been described. proportions, characteristic ratios of D Wright further recognizes a probable to R individuals will be formed as the Black+white Brindle DU-Brindle DiJ. Black Dil.. Dilute Dll.- ; Black Brindle Fawn White Total (harlequin) +white -(-white -t-white Black brindle fawn

A Harleqain (B & W) x Harlequin (B & W).. 188 6 6 25 10 14 2 4 255 B Brindlo x BrindJe 1 2 9 1 4 2 420 12 60 5 516 C Fawn x Fawn 2 37 4 43 D Dil-Blk x DU-Blk 4 40 44 E Brindle x Brindle & Wht 2 16 1 2 21 F Fawn x Fawn & Wht 2 2 G Blk. x Harlequin (B & W) 7 9 1 2 19 H Blk. x DU.-Blk 3 2 5 I Fawn x Dil.-Fawn 14 2 16 J Brindle x Dil.-Brindle 23 8 6 • 37 K Brindle x Harlequin 4 3 2 2 11 L BrindJe x Black 1 9 1 7 4 22 M Brindle x Dil.-Blk. & Wht 1 1 1 3 N Brindle x Fawn 1 1 251 5 166 9 433 •0 Brindle x Dil.-Blk 3 5 1 4 10 2 5 2 32 P Fawn x Black 1 2 1 4 0 Fawn x Harlequin 2 2 4 R Fawn x DU.-Blk 1 4 6 1 1 13 S Blk. x Dil.-Blk. & Wht 1 2 2 5 T Harlequin x Dil.-Blk 3 2 5 U Harlequin i Brindle & Wht 5 1 6 V Harlequin x Dil.-Brindle 1 1 3 2 7 8 W Blk. x Dil.-Brindle 2 3 2 1 13 X Fawn x Dil.-Brindle 6 5 2 24 Y Brindle x Dil.-Fawn 17 6 1 1 Z Brindle & Wht. x Dil.-Fawn 1 2 A' Brindle & Wht. x Fawn 1 . 1 3 B' Harlequin x Dil.-Blk 1 1 1 5 C Dil.-Brind. x DU.-Fawn 5 D> Harlequin x DU.-Fawn E' DU.'Fawn x Dil.-Blk 1 1 2 4 Fi Fawn x Dil.-Blk. & Wht 2 3 2 7 G> Harlequin x White 1 1 2 Hi Brindle x White 5 2 7 1 I Dil.-Fawn x Fawn & Wht 2 1 3

i Total 218 18 17 7 59 70 798 50 319 23 4 1583 3.14 The Journal of Heredity result of random matings of D individ- TABLE II u'als inter se as follows: Matings D and D D animals crossed inUr se

D 6 Ratio of DD or DR Mating Dilute Ratio of animals in animals to RR in Intense population progeny of random matings A 233 18 B 487 29 C 39 4 (a) 1 DD : 2 DR.. E 1 15 20 (b) 1 DD : 1 DR.. F 0 35

TABLE III Crossing E 'animals- inter le.

Matings D and d Ratio of E to E'toe' Ratio of E types with animals obtained by in a mixed population random matings Mating D d 1 (0) 1EE 1EE'- lEe>. 32 E 3E1 le1 (1) 2EE 1EE> lEei. 60 E 3E1 le1 H : 3 9 1 1 I. . 14 2 (c) 2EE 2EE' lEe>. 75 E 8E le 29 8 M.. ••'.'.' 2 • 1 1 0 -.,..-... , .,-, 24 • 8 Crosses of E x E R 8 5 S 5 T 3 "2 Ratio of E types with- Ratio of E to E' to e> V 4 3 in a mixed population animals obtained by w...:. .• •: 6 ' 2 random matings x 5 23 1 z"'."". 1 (a) 1EE 1EE. : lEe'.. 4E IE. le. B1 . . . 2 ' 1 (b) 2EE 1EE- : lEe'.. 6E 1E> le' D- • 1 (c) 2EE 2EE> : lEe... 7E 2E« le. F' ' 1 4 . 3 I' :• 3 Table V shows a' combination of "all matings involving .the factor E. If (a) Total 140 43 ±3 8 the E x E matings be-first-considered, (b) Expected on 3 : 1 ratio 137^46 ±3.9 it will be noted that the ratio of 309E (c) Expected on 2 : 1 ratio 122-61 ±4.3 1 l Difference (a) and (b) 3 ±5.4 to 22E to 2e approximates very closely Difference (a) and (c) 18±5.7 the numbers expected on a 75 to 8 to 1 Table. IV sh6ws' the results of mating distribution. Referring to the list of dilute animals inter se. While the matings given above, it will be seen that the 75 :8 : 1 ratio depends upon numbers are small the results are con- 1 the supposition that EE and EE sistent with the supposition that dilute individuals occur with equal frequency forms are hypostatic to intense and all in a mixed population and which are fifty-three animals obtained are dilute each of them twice as numerous ' as pigmented. Ee1 animals. This is not at all un- TABLE IV likely, for blacks or harlequins (E) Matings D and d arid brindles ' (EL) are about equally popular in Great Dane breeding, and Mating D both of them appear far more frequently than do fawns (e1)- D.. 44 TABLE V C1.. 5 Matings of EE1 and e1 E1.. 4 Cross EXE Total. 53 Mating E E.1 e1

l A 235 16 for partial extension, and e for D 44 restriction of black pigment G 1-7 3 In the mixed population of Great H . 5 S . 1 • 2- •2 Danes under consideration, the ratio 5 1 1 T . . . of E, E , and e types obtained when E D'W.... 2 1 forms are crossed inter •se or with e1 wiH be characteristically distinct' and Total 309 22 • 2 will give some idea as to the degree of 75 :8 : 1 ratio. . . . 300 32 4 inbreeding and selection involved. Thus: 316 The Journal of Heredity-

Cross E X el Cross E'XE1

Mating E E» Mating E E> e1 P 1 2 Q 2 2 B 9 442 65 R 5 7 1 E 19 2 D' 1 31 6 E> 2 2 F1 3 4 Totals 9 492 73±5.38 SI ratio 510 64±5.08 Totals 13 16 4 Difference 9±7.4 7:2:1 ratio 22.4 6.4 3.2

Cross e1 X el If a triple allelomorph series is in- volved between the factors E, El, and 1 1 1 e , the only types of matings which Mating E E e should give all three phenotypes are E x E, E x e1, and E x E1. Such, how- C ... 2 41 ever, is not actually the case. We F 2 find, for example, that there are nine E I 16 1 l Ii 2 1 animals obtained in matings of E x E individuals in a total of 574 offspring. Totals . 4 60 Similarly, there is one E individual in matings of E1 x e1 in a total of 477 1 Cross EXE1 offspring; and finally, there are four E individuals in a total of sixty-four progeny produced by e1 x el matings. Mating E E' e1 Some, or perhaps all of these exceptions might be explained by errors in re- K 7 2 2 cording parents or in the stud books. L 11 7 4 There appears, however, to be another M 1 2 possible explanation which should re- O 8 17 7 6 ceive consideration. Vu 1 4 2 If one examines a large number of W 2 5 1 specimens of brindle Great Danes, he Totals 36 37 16 finds that they vary greatly in the amount of black pigment which they possess. Some of them are so nearly Cross E»Xel fawn as to have only a small spot of dark hairs, while others are almost Mating E E' e1 indistinguishable from blacks. This is a common condition in all brindle and similar patterns. It is found in yellow N 1 257 174 X 11 2 mice, tabby cats, and in agouti Y 17 7 rabbits, mice, and guinea-pigs. That it 2 1 1 is a recognized trouble maker in breeding A1 1 1 C1 5 brindle Great Danes is shown by the following quotation from Leighton (loc. Totals 1 292 185 ±7 18 cit.): "When brindle Great Danes have 2-1 ratio 318 159 ±6 94 Difference 26 ±9.9 been continuously bred together it has been found that they get darker and Little and Jones: Inheritance of Color in Great Danes 317 that the peculiar striping disappears, is complicated because of great varia- and in that case the introduction of a bility in the degree of spotting, and of good fawn into the strain is advisable." incompleteness of dominance ia many It seems therefore entirely probable cases, also because genetically different that at least a part of the nine blacks types of spotting all show themselves (E) appearing in the E'xE1 matings as simple contrasts between colored and the one black appearing in the and white areas. Even with all these E'xe1 matings represent brindles of handicaps, however, the data obtained this extremely dark or blackened type, from the A. K. C. stud books indicate while the four brindles (E1) which that there are at least two genetically appear in matings of fawn x fawn may different types of spotting in Great well be due to the fact that one of their Danes. We may first consider the more parents was an extremely light brindle striking of these, namely harlequin in which the black was so reduced that spottings. (Plate 1, Fig. 2.) it appeared phenotypically like a fawn Animals of this type when crossed and was so recorded. The occurrence together have given, in addition to of exceptions of this type is therefore harlequin, a considerable number of self expected, provided that the brindle animals as shown in Table VI. From a pattern of Great Danes behaves as all fancier's point of view, harlequins by -other similar pattern factors hitherto inbreeding continually tend to grow too studied in mammals. light, that is, to have too little black pigment. The method followed to cor- (c) Factor H for harlequin spotting, rect this is to cross harlequin with self h for absence of harlequin spotting intense blacks. (Fig. 12, number 3.) or self coat. This leads to an increase in black Inheritance of any form of spotting areas on the resulting harlequins.

TABLE VI

Matings HXH Matings hXh

Mating H h Mating H h

A 188 63 B 1 515 Totals 188 63 ±4 63 C 43 Expected 3 :1 ratio 188 63 ±4.63 D •44 Expected 8 • 1 ratio 221 31 ±3 57 H... 5 Expected 15 : 1 ratio 235 16 ±2.61 I 16 T L 1 21 Mating!. Hxh N 433 o 3 29 P 4 Mating H h r R 13 1 w 8 X . 13 G 7 12 Y 24 K. 4 7 Cl c •Q 2 2 E1 4 V 1 6 B> 1 2 Totals.. .. 5 1214 D1 1 Totals (a) 15 30 ±2.13 Expected (a) 1 : 1 ratio.. . 22 22 ±2.26 Expected (b) 2 :1 ratio. . . 30 15 ±2.13 Expected (d) 3 :1 ratio. . 34 11 ±1.94 Difference (a)X(b) 3.1 Diff. n , p. E. Diff. "'" Difference (a) and (c). . . . 15± 3.0 Diff. - n p. E. of Diff. Difference (a) and (d) ... 19± 2.89 p. E. of Diff. 318 The Journal of Heredity

Because of the generality ' of this" The harlequin spotting factor appears- practice one might expect that the to be not unlike the dominant spotting great majority of harlequins would be observed by Barrows and Phillips in heterozygous and that the result of cocker spaniels, although, of course, crossing two harlequins would be to the actual distribution of the spots- approximate a ratio of three harlequins differs in the two forms, those of the to one self colored. This as can be Great Danes being far more irregular in seen from Table VI is exactly the result outline. obtained, and we may therefore con- sider that it is extremely probable that (d) The Factor S for Self Color, and s for harlequin represents a form of spotting "piebald" spotting depending upon a factor epistatic to The term "piebald spotting" is self colored. Furthermore, when harle- perhaps a misnomer, for apparently the quins are crossed with self blacks, the only manifestation of this type of small number of young obtained show spotting which exists in Great Danes is a ratio which is not significantly differ- the occasional occurrence of animals ent from a one to one ratio. This with a white chest spot or with white supports the view that the harlequins feet, or with both. Such an animal is used for breeding are commonly hetero- shown in Fig. 12, No.l. Such forms zygous. The matings of animals lack- are. not desired and are rigorously se- ing the harlequin spotting factor are lected against by fanciers. Inasmuch, last to be considered. These have however, as, their appearance depends given a total of 1,219 Offspring. Of upon an hypostatic factor, the entire these, five, or less than four-tenths of elimination'from any strain has proved one per cent, are harlequin, and the to be difficult, and they still crop out remainder are self as expected. It is at rare intervals. That they ' appear extremely likely that these five excep- less frequently than animals possessing- tions are due to stud-book errors, for the other hypostatic factors already they occur so rarely that it is hard to considered is shown by Table VII. believe that they are genetically signifi- Here matings of self x self animals cant. have given 1,214 offspring, of which

TABLE VIII

Matings S X S Matings S X s

Mating Mating S

B 503 I 12 E 19 2 C 43 F D 40 M 2 H 5 S 5 I 16 z 1 37 T A1 2 1 L'.'.'.'.' ...... '.'•'.'". 21 F 2 5 N 432 I' 3 O 24 Total 36 . 7 ±1 .6.5 P 4 Expected 2 29 14 ±2 .7 R . 13 Expected 3 32 11 .±1 .93 W 8 Expected 5 36 7 ±1 .63 X 13 : Y 25 ' C1 1 E I 1 Total (a) 1192 22 ±3.14 Expected : 1 (b) 1079 135 ±7 38 Difference (a) and (c) 54±6.5 Expected 15 :1 (c) 1138 76 ±5.69 Difference (a) and (d) 12±4.9 Expected 35:1 (d) 1180 34 ±3.87 Little and Jones: Inheritance of Color in Great Danes 319 twenty-two are spotted. At the bottom separate series, until their relationship of the table, a comparison between the with the'yellow of pointers and English observed figures and the numbers ex- setters is definitely established. We pected on 8 : 1, 15 : 1, and 35 : 1 ratios have, however, chosen to consider them is made. It will be noted that the as modifications of E until they arc 35 : 1 ratio is most closely approxi- proven to be independent. (4) D mated and that this ratio probably factor for intensity of coat color, modi- means that there are two SS to one Ss fication of which, d, produces dilute individuals in a mixed population of pigmentation of black, brown, or yellow self Great Danes. coat color. This factor is distinct from Confirmatory evidence is obtained the albino series and is comparable to from the matings of self with spotted the similarly designated factor de- animals, also shown in Table vn. scribed by Castle and Little (1909) Here, a 5 : 1 ratio is expected if two out in mice, or to the maltese dilution of of each three self animals are SS in cats described by Doncaster (1905), and formula. So far as the numbers ob- confirmed by Whiting (1918), or to the tained are concerned, this expectation dilution factor described by Castle is exactly fulfilled, although the numbers and others (1909) in rabbits. (5) H are so small that without the additional factor for irregular white spotting evidence from the cross of self animals (harlequin spotting)—many irregular inter se it could not properly be con- colored spots on a white ground. The sidered as definitely proving the point spotting is apparently independent of in question. regional distribution on the body and is characteristic of harlequin Great (e) List of factors knciin to date in dogs Danes, but also possibly found in cocker spaniels and English setters, h modi- • • It may be useful at this point to make fication of this factor producing, in the a list of color factors recognized in dogs, absence of any other factors for spotting, in order that their relations may be a coat without any white spotting. considered and that future experiments (6) S factor for self or solid coat color, may be planned with them in view. a hypostatic modification of 'which, s, They are as follows: produces animals with a small amount . (1) C,.the color factor, modification of l of white, possibly confined to a chest which, c , produces partial albinism; spot or single foot spot. Quite prob- (2) B, factor for black pigmentation, ably from a mixed population such 55 modification of which, b, produces brown animals might be selected to form a or coat color, (3) E for ex- race of true piebald animals with a con- tension of black and brown pigmentation, siderable amount of white in the coat. modification of which, e, produces orange In addition to the above, several or lemon-yellow coat color. It is pos- color phases occur which are undoubt- sible that the black and pattern edly referable to mendelizing factors. and the brindle and fawn .coat patterns These may be listed as follows: (1) may fall into this series. The two Black and tan coat pattern, apparently- latter are therefore, for the present; l recessive to solid coat pattern. (2) classed as follows: E modification of E Dominant yellow such as occurs in producing brindled coat pattern such as dachshunds. (3) R, a roaning pattern. is found in Great Danes, bulldogs, l This factor is seen in so-called "tigered" Boston terriers, and greyhounds. e l dachshunds and possibly in Blue modification hypostatic to E producing collies. It is in-all probability domi- fawn coat color ound in Great Danes, nant to solid coat and independent of greyhounds, bulldogs, and Boston ter- the other factors listed above. • , riers. Further experimentation may serve to show that El and el are in reality hot modifications of £ but are (J) The Value of Dogs as Genetic Material genetically in a different allelomorphic Recent investigations of Malone series. One might, at present, if he so (1918) have shown that there are In desired, class them as members of a dogs two classes of sperm, bearing 320 The Journal of Heredity eleven and ten chromosomes respec- the fawns. Black "*(E) 'animals may tively. This being the case, it seems carry either brindle (E1) or fawn (e1) probable that dogs represent, even in but not both; brindles (El) may carry spite of their slow breeding and large fawn (el) but not black (E), and fawns size, the best material available among (e1) can carry neither brindle (E1) nor the mammals for a relatively complete black (E). genetic analysis. They are found in 3. Harlequin spotting (H) is epistatic more color varieties than occur in any to solid coat color (h) and apparently other domesticated animals. They have differs from it by a single mendelizing more structural differences and a greater factor. size difference between breeds as well 4. Minute white spots on the chest as a greater difference in number of or on the feet occur rarely among the young per litter than are found in other progeny of solid colored animals. Their mammals. There is apparently com- appearance is probably due to a factor plete fertility between different breeds. (s) for piebald spotting which is hy- Artificial insemination has been tried postatic to its allelomorph (S) for self (Iwanoff, 1903) and has been found coat color. possible,- a fact which might enable experimenters to overcome any me- chanical difficulties in crossing very LITERATURE CITED large with very small breeds. They possess more clearly denned instincts, BARROWS, W. M., and PHILLIPS, J. N. (1915): Color in Cocker Spaniels. Jour. Heredity, characterizing various varieties than 6: 387-397. do other mammals. To sum up, there- CASTLE, W. E., et al. (1909): Inheritance in fore, it may be stated that if an in- Rabbits. Pub. Carnegie Inst. of Wash. vestigator is willing to wait for his No. 114, 70 pp. 4 plates. CASTLE, W. E., and LITTLE, C. C. (1909): results, dogs provide a field unequalled The Peculiar Inheritance of Pink-Eyes among mammals in the respects above among Colored Mice. Sci. N. S. 30: outlined. 313-314. DONCASTER, L. (1905): On the Inheritance of Tortoise Shell and Related Colors in Cats. IV. SUMMARY AND CONCLUSIONS Proc. Camb. (Eng.) Phil. Soc, 13: pt. I, From a study of the breeding records p. 35. IWANOFF, E. J. (1903): Ueber kunstliche of Great Danes in the American Kennel Befruchtung von Saugetieren. Vorl. Mitt. Club Stud Books, the following con- Biol. Zeatralbl., 23: s. 640. clusions can be drawn: LANG, A. (1910): Ueber Alternative Vererbung 1. There is a single mendelizing bei Hunden. Zeit. f. Abst. Ver., 3: 1-33. LEIGHTON R. (1907): The New Book of the factorial difference between the intense Dog. Cassell & Co., London, Eng. xvi + pigmented (black, brindle, and fawn) 620 pp. varieties on the one hand, and the LITTLE, C. C. (1911): The "Dilute" Forms of dilute varieties (dilute black, dilute Yellow Mice. Sci. N. S., 33: 896-897. LITTLE, C. C. (1914): Inheritance of Coat brindle, and dilute fawn) on the other Color in Pointer Dogs. Jour. Hered. 5: hand. The factor D for intensity is 244-248. epistatic to its allelomorph d—the MALONE, J. Y. (1918): Spermatogenesis in the Dog. Trans. Amer. Micr. Soc., 37: 97- factor for dilution. 100. 2 plates. 2. The three coat conditions repre- PEARSON, K., NETTLESHIP, E., and USHER, sented by solid black, brindle, and C. H. (1913): A Monograph on Albinism in fawn are dependent upon three mutually Man, Part II, 460-512. allelomorphic factors: E for full ex- "STONHENGE" (WALSH, T. H) (1873): The 1 Dog. Lee and Shepard, viii+470 pp. tension of black pigment, E for its WHITING, P. W. (1918): Inheritance of Coat- partial extension as seen in the brindling Color in Cats. Jour. Exp. Zool., 25: 539- pattern, and e1 for its restriction to the 569. 2 plates. WRIGHT, S (1918): Color Inheritance in muzzle, nose, feet, and a small area Mammals. The Dog. Jour. Heredity, 9: near the eyes—a condition typical of 87-90.