POULTRY NOTES — 1909. 



107 



Inheritance oif Shank Color. 



The shank color of these hybrids furnishes another instance 

 of sex-Hmited inheritance, such as has already been described 

 for plumage color (cf. pp. 87-89 supra). The evidence for a 

 sex-determined segregation of characters in the F^ generation 

 is just as definite and convincing in the case of shank color as 

 it has been in plumage color. It has already been suggested 

 by Bateson {loc. cit.) that shank color in fowls in general shows 

 a tendency towards sex limitation in its inheritance. Thus he 

 says {loc. cit. p. 186) : "From many signs we know that there 

 exists some complex relation between the colour of the shanks 

 in fowls generally, and sexual dififerentiation. Some years ago 

 v/e described a case of this kind in which the Indian Game 5 

 X White Leghorn ^ always gave F^ yellow-shanked like both 

 the parent breeds. But White Leghorn 5 x Indian Game q 

 gave cocks yellow-shanked like the parents, while the hens 

 came with a good deal of pigment in the shanks ranging to 

 nearly a full black. 



Another case illustrating this relationship between sex and 

 shank-colour is to be seen in the newly made breed called Black 

 Leghorn. According to the fanciers' ideal both sexes should 

 have full yellow shanks. There is no difficulty in getting this 

 quality in the cocks, but hitherto clear yellow-shanked hens 

 have been very rare, and the same difficulty is encountered in 

 breeding Black Wyandottes." 



As is indicated in Table 2 (page 85) both Cornish Indian 

 Game and Barred Plymouth Rock are yellow-shanked breeds. 

 The facts as to the distribution of shank color in the F, hybrids 

 are shown in the following- table. 



Table 12. 

 Shozmng the Shank Color of F^^ Hybrids. 



Matin<:. 



Shanks of males. 



Shanks of females. 



Barred Rock cf x Cornish 9 



Yellow 





Cornish j' Barred Rock 9 



Yellow 



Black 









The data are seen to parallel exactly those for the inheritance 

 of barring. In the mating in one direction all the offspring 

 are yellow-shanked, whereas in the reciprocal cross the males 



