COLOR MUTATIONS IN MICE OF PEROMYSCUS 



305 



doubtful cases have been encountered. It is not worth while to 

 detail the numerous matings which have been made within the 

 palhd stock. It should be pointed out, however, that the same 

 excess of recessives (here four out of eleven) was found among the 

 offspring of the original heterozygous (?) parents, as in the case 



TABLE 5 



Adult pallids 



TABLE 6 



Juvenile pallids 



Color-screen readings (mean) 



Red .' 



Green 



Blue-violet 



Equivalents in black, white, and color (mean) 



Black 



White 



Color 



31.75 

 25.00 

 22.00 



68.25 



22.00 



9.75 



of all but one of the strains of yellows. At best, however, these 

 combined figures merely suggest a possibility. 



The following figures (tables 5 and 6) express the results of 

 color determinations of twelve adult and two juvenile skins of 

 the pallid mice (see also pi. 2). It is evident that the juve- 

 nile animals surpass the adult in black and white (i.e., are 

 more gray), being relatively deficient in color. The ratio of red 



THE JOURNAL OF EXPERIMENTAL ZOOLOGY, VOL. 36, NO. 3 



