470 THE AM ERIC AX X ATI RATA ><T [Vol. LV 



In both rats and mice, this gene greatly recluc(>s the production 

 of black and brown hair pigment, but leaves yellow undisturbed. 

 The linkage of pink-eye to albinism in both forms gives added 



A gene for pink-eye is also known m the guiiK ;i |)iu' (('iisth' 

 M4)^ but it has not yet been estahlislicd thai piiik-(/y(' and 

 albinism are linked in this form. It may be unsat'c to homologi/e 

 strictly the gene for pink-eye in mice and rats with the gene in 

 euinea pigs whicli produces similar somatic effects. A deep 

 red-eyed (almost l)lack-eyed) yellow rat has also been described 

 (Castle. '14).^ The gene Un- wd-vyi^ is linked to the gene for 

 pink-eye. This mutation lias not yd been observed in mice. 

 Brown varieties of mice ami uiiiiifa pii;s have been known for a 

 long time. Brown rabbits i tlir Havana variely) and the brown 

 roof rat (Patterson. '20 1 • aiv nvcnt pfodu.'tions. While no 



the form should be possible and ll^ diM-ovciy is only a matter of 

 time and opportunity. A sci df (juadi iii)!*' allelomorphs in the 

 guinea pig includes intense color, .lilmion. ruby-(\v('d dilution 

 and Himalayan albinism (Wriizlit, "l.'))." Soon at'ter ihesc I'onns 

 were found, Whiting and Kin- CIS)' reported ruliy-eyed dilu- 

 tion in rats, an allelomorph of both color and albinism. While 

 Whiting and King nse.l the same symbol, c,. for this gene that 



other aiiimaU. as ni the cohir vaneth -^ of ilir horse and the ass, 

 for example, and in the ca^' of the l)rnsoi>li ila species. 



