266 



THE AMERICAN NATUBALIST [Vol. LIIl 



I have frequontly produced spottfd Himalayan rabbits, which 

 ^\ould show partic'uhir types of white spotting, as Dutch or 

 English, on the feebly pigmented Hnnalayan background (as 

 has also Punnett). and Wright has produced w^hole series of 

 varieties of spotted red-eyed and spotted dilute guinea-pigs. 



Among certain rodents pink-eyed varieties occur which are 

 due to variation in a genetic locus wholly distinct from that 

 which is responsible for albinism. Such are the well-known 

 pink-eyed varieties of mice having colored coats. Here the 

 retina and the fur alike have a greatly reduced amount of black 

 and brown pigmentation as compared with normal individuals, 

 though yellow is unaffected. Pink-eyed rats and pink-eyed 

 guinea-pigs are similar in appearance and in genetic behavior 

 to pink-eyed mice. When crossed with the albino variety of 

 the same species, they produce fully colored offspring as regards 

 both eye and coat. The gene for pink-eye is thus seen to be 

 complementary to the gene for albinism, with which it is known 

 to be "linked" in rats and mice. AVhether the two are also 

 "linked" in guinea-pigs has not yet been ascertained. 



Among mammals other than rodents albino and pink-eyed 

 varieties are not certainly knowm to occur, though white-spotted 

 and black-eyed white varieties are common. It is thus an open 

 question whether the same genetic loci are found among them 

 as among rodents. Bateson has pointed out similarities be- 

 twt'fMi a color variety of cat, the so-called Siamese, and the 

 IIiniala>an variety of rabbit. Both are born white or nearly 

 white and later become more heavily pigmented. I may add 

 (2) that both are inherited as recessives and (8) that in both 

 varieties yellow pigment is largely or wdiolly suppressed, which 

 is characteristic of the albino variation, but not of the pink-eye 

 variation of rodents. 



Wright has suggested that blondism among human beings 

 fwhich when extreme in character is commonly known as al- 

 l)inism) is similar in nature to the albinism of rodents, being a 

 graded series of allelomor]^hs similar to the series wdiich he has 



It thus appears prol)al)]c that the same tivtietic locus, which 

 occurs in rodents and wliu-h h,i- 1 .a'hd the "color factor," 



The ca e of the Siamese <■..• i,,.. s „„ ,| i., „ir for s.mie >ear, 

 deserving of more careful stu 1\ kiii<r nppoitunity for such 



study myself, I sent out an inquiry several years ago through 



