COLOR MUTATIONS IN MICE OF PEROMYSCUS 



295 



of 22 cage-born offspring, of which 14 (5 cf and 9 9) were of 

 the wdld type, while 8 (5 cf and 3 9) were 'yellows.' As in 

 the case of the 'a' strain, the proportion of recessives among the 

 offspring of these presumably heterozygous parents was some- 

 what too high, though, as before, the total number of individuals 



TABLE 1 

 'A' yellows 



was not sufficient to justify any conclusions from this fact. 

 It will be noted that in this case the proportion of males among 

 the yellows was much higher than among the wild type, the re- 

 verse being true of the first strain. Such differences are prob- 

 ably accidental. 



