CORRELATION OF CHARACTERISTICS IN HYBRIDS. 



45 



which is slightly less than half of a perfect correlation (i). This result 

 indicates that there is a general tendency to pigmentation in the body ; 

 that this affects both skin and hair, but for some reason a black hair 

 color may be associated with a light-colored skin. Just why this is 

 can not at present be answered. Evidently hair color depends upon 

 additional factors to those merely which determine skin pigmentation. 



II. CORRELATION BETWEEN COLOR OF THE SKIN AND FORM OF THE HAIR 



IN THE F 2 GENERATION. 



The correlation surface is given in table 34. 



TABLE 34. Correlation between color of the skin and form of the hair. 



N. B. The tabular entries indicate the frequency with which the given correlation occurs. 



The correlation calculated from table 34 is + 0.043 =*= 0.080. 

 Expressed in English this means that there is no evidence of any corre- 

 lation at all. An inspection of table 34 shows that one of the two ex- 

 tracted full black-skinned individuals had straight hair, and that one 

 of the extracted white-skinned individuals had woolly hair. Black skin 

 color and woolly hair are closely associated in the pure-bred negro, but 

 the association is, so to say, accidental. The determiners for the two 

 traits dissociate in the germ-cells of the hybrids and reappear in the 

 next generation in all possible combinations. 



The lack of correlation between two, at least, of the negro's char- 

 acteristics affords additional proof of our conclusion that skin color does 

 not blend, but segregates. In what other mechanism than that afforded 

 by segregation in the germ-cells have we an explanation of the result ? 



The fact that two, at least, of the negro's traits are inherited 

 wholly independently opens the way for some interesting considerations 

 of a social nature. As is often the case, we have let one character 

 skin color epitomize the totality of the racial characters of the negro. 

 Recognizing the inadequacy of the average black African negro to play 

 a part in our highly developed society a natural stigma has become 

 attached to black skin color. Our social distinctions are based on that 

 skin color; we have separate railway cars and schools for "blacks" 

 and "whites." Meanwhile, in consequence of hybridization and segre- 

 gation of characters, we have black-skinned persons with straight hair, 



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