STUDIES OF COAT-COLOR AND FOOT PIGMENTA- 

 TION IN SUBSPECIFIC HYBRIDS OF 

 PEROMYSCL'S EREMICUS 



F. B. SUMXER AND R. R. HUESTIS. 



I. INTRODUCTION. 



In several previous papers * the senior author has reported upon 

 inheritanre, variation, correlation and allied phenomena in crosses 

 between several subspecies of Peromyscus maniculatus. A con- 

 siderable number of measurable characters were dealt with in the 

 course of these studies, some of these relating to the absolute or 

 pro; of various bodily parts, others to the pigmenta- 



tion of the hair and skin. 



It was early evident not only that the characters distinguishing 

 twn sul s, taken collectively, did not depend upon single men- 



delian all Imnorphs, but that the same was true of each of the vari- 

 ous sul 'ic differences, taken separately. So far as studied, 



all of tbe-e characters followed the " blending " type of inheritance. 

 If they were dependent upon mendelian factors at all, several or 

 main .if these were concerned in the production of each character 

 cliff- Moreover, studies of correlation showed that in many 



cases these separate characters were inherited independently of 

 "tie another. 



\liout three years ago, the junior author began the study of an- 

 other species of Peromyscus, P. eremicus, a form differing suffi- 

 ciently fr>m I } . maniculatus to be assigned to another subgenus. 2 

 Two subspecies were dealt with, P. crcmicus eremicus and P. e. 

 i>\itcrculu$. The parent stock of the former race was trapped 

 in Death Valley, California, in 1920, the latter animals were taken 

 in the neighborhood of La Jolla. In appearance, these two geo- 

 graphic races differ in the same manner as do desert and coast- 

 dwelling representatives of various other species of rodents. The 



i Journal of Experimental Zoology, Oct., 1923, and papers therein cited. 

 - l'r .1 hricf summary of the results of these studies see Huestis, Proc. Nat. 

 Acad. of Sci., 1923. A fuller account is now in press. 



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