Little and Jones: Inheritance of Color in Great Danes 319 



twenty-two are spotted. At the bottom 

 of the table, a comparison between the 

 observed figures and the numbers ex- 

 pected on 8 : 1, 15 : 1, and 35 : 1 ratios 

 is made. It will be noted that the 

 35 : 1 ratio is most closely . approxi- 

 mated and that this ratio probably 

 means that there are two SS to one Ss 

 individuals in a mixed population of 

 self Great Danes. 



Confirmatory evidence is obtained 

 from the matings of self with spotted 

 animals, also shown in Table vn. 

 Here, a 5 : 1 ratio is expected if two out 

 of each three self animals are SS in 

 formula. So far as the numbers ob- 

 tained are concerned, this expectation 

 is exactly fulfilled, although the numbers 

 are so small that without the additional 

 evidence from the cross of self animals 

 inter se it could not properly be con- 

 sidered as definitely proving the point 

 in question. 



{e) List of factors known to date in dogs 



It may be useful at this point to make 

 a list of color factors recognized in dogs, 

 in order that their relations may be 

 considered and that future experiments 

 may be planned with them in view. 

 They are as follows: 



(1) C, the color factor, modification of 

 which, c\ produces partial albinism; 

 (2) B, factor for black pigmentation, 

 modification of which, b, produces brown 

 or chocolate coat color, (3) E for ex- 

 tension of black and brown pigmentation, 

 modification of which, e, produces orange 

 or lemon-yellow coat color. It is pos- 

 sible that the black and tan pattern 

 and the brindle and fawn coat patterns 

 may fall into this series. The two 

 latter are therefore, for the present, 

 classed as follows: E^ modification of E 

 producing brindled coat pattern such as 

 is found in Great Danes, bulldogs, 

 Boston terriers, and greyhounds, e^ 

 modification h3'postatic to E^ producing 

 fawn coat color ound in Great Danes, 

 greyhounds, bulldogs, and Boston ter- 

 riers. Further experimentation may 

 serve to show that E^ and e^ are in 

 reality not modifications of E but are 

 genetically in a different allelomorphic 

 series. One might, at present, if he so 

 desired, class them as members of a 



separate series, until their relationship 

 with the yellow of pointers and English 

 setters is definitely established. We 

 have, however, chosen to consider them 

 as modifications of E until they are 

 proven to be independent. (4) D 

 factor for intensity of coat color, modi- 

 fication of which, d, produces dilute 

 pigmentation of black, brown, or yellow 

 coat color. This factor is distinct froin 

 the albino series and is comparable to 

 the similarly designated factor de- 

 scribed by Castle and Little (1909) 

 in mice, or to the maltese dilution of 

 cats described by Doncaster (1905), and 

 confirmed by Whiting (1918), or to the 

 dilution factor described by Castle 

 and others (1909) in rabbits. (5) H 

 factor for irregular white spotting 

 (harlequin spotting) — many irregular 

 colored spots on a white ground. The 

 spotting is apparently independent of 

 regional distribution on the body and 

 is characteristic of harlequin Great 

 Danes, but also possibly found in cocker 

 spaniels and English setters, h modi- 

 fication of this factor producing, in the 

 absence of any other factors for spotting, 

 a coat without any white spotting. 

 (6) 5 factor for self or solid coat color, 

 a hypostatic modification of which, s, 

 produces animals with a small amount 

 of white, possibly confined to a chest 

 spot or single foot spot. Quite prob- 

 ably from a mixed population such 55 

 animals might be selected to form a 

 race of true piebald animals with a con- 

 siderable amount of white in the coat. 

 In addition to the above, several 

 color phases occur which are undoubt- 

 edly referable to mendelizing factors. 

 These may be listed as follows: (1) 

 Black and tan coat pattern, apparently 

 recessive to solid coat pattern. (2) 

 Dominant yellow such as occurs in 

 dachshunds. (3) R, a roaning pattern. 

 This factor is seen in so-called "tigered " 

 dachshunds and possibly in Blue Merle 

 collies. It is in all probability domi- 

 nant to solid coat and independent of 

 the other factors listed above. 



(/) TJw Value of Dogs as Genetic Material 



Recent investigations of Malone 

 (1918) have shown that there are in 

 dogs two classes of sperm, bearing 



