HEREDITY OF SKIN COLOR IN NEGRO-WHITE CROSSES. 



Bv Charles B. Davenport. 



A. STATEMENT OF THE PROBLEM. 



Two years ago (igio) Mrs. Davenport and I published some 

 measurements made on the color of the skin of descendants of matings 

 between negroes and Caucasians; and we concluded that, in opposi- 

 tion to current belief, our data afforded evidence that there is segre- 

 gation in skin color. We concluded that, while skin color is inherited 

 in typical fashion, the pigmentation of the full-blooded negro is not 

 dependent on two (i.e., the duplex) determiners, "but perhaps a myriad 

 of them." Lang (1911,* p. 122) cites these results with approval and 

 brings them in line with other studies in which the presence of several 

 factors for a single character is indicated, but he would query our 

 statement "that oflspil-ig are rarely darker than the darker parent." 

 This statement merelj' summarized the empirical result obtained from 

 the four quantitatively studied families and was not in complete 

 harmony with the theoretical explanation offered — a disaccord upon 

 which we laid no emphasis because our quantitative data were so 

 limited. Our concluding sentence was as follows : 



AU studies indicate that blonds lack one or more tmits that brunets 

 possess; that the negro skin possesses still additional units; that individuals 

 with the header skin pigmentation may have slight pigmentation covered 

 over — ^hj'postatic, evidence of this condition appearing in the light offspring 

 of such hybrids in the second or third generation; and that first-generation 

 hybrids frequently show, somatically, a color grade less than that which they 

 carry potentially and may segregate in their germ<ells. 



The need for additional data was, however, recognized as great. 



B. METHOD OF INVESTt^ATION. 



The difficulty of getting the desired data is considerable, especially 

 in our Southern States, where all matings of blacks and whites are 

 illegal and the genealogies of "colored" people are usually either diffi- 

 cult to obtain or else unreliable. After having discussed the matter 

 with persons of experience in other countries, as well as in the Southern 

 States, it was decided that the best available field for study would be 

 the islands of Bermuda and Jamaica. Funds were provided to pay 

 the salary and expense of a field worker to collect the data, through 

 the generosity of Mrs. E. H. Harriman. Science is greatly indebted 



* These numbers refer to the particular paper of the author as listed in the " Litera- 

 ture cited," p. 48. 



