No. 527] SKIN PIGMENTATION IN M AN 



CUT 



the children show a significantly greater pigmentation 

 than the darker parent, and one is lighter than the 

 lighter parent. There is clear evidence of segregation 

 of the skin pigmentation. 



The J. family is important because of the mating of 

 an " almost white" first generation mulatto with a male 

 mulatto who is more than twice as dark. Of the four 

 children measured three are nearly white, whiter than 

 the mother, and one is as dark as the father. The series 

 runs: 8.5, 10, 10, 28. A segregation of practically white 

 and half dark (grandparental colors) takes place here 

 also. 



The H. family has also several points of interest. A 

 lighter and darker mulatto parent (black, 30 per cent, 

 and 36 per cent., respectively) from four mulatto grand- 

 parents have children ranging in amount of black pig- 

 ment from 27 to 39; these extremes being somewhat 

 lighter and somewhat darker, respectively, than the pa- 

 rents. No white appears. This result is like that ob- 

 tained in many Caucasian families with " intermediate " 

 skin color; where two "intermediate" parents (that 

 apparently do not have hypostatic "blond") breed true. 

 They behave like ' ' pure dominants. ' ' 



The C. family gives much the same result. Two second 

 generation mulattoes of rather dark type have children 

 of this dark type only. None of them exceed the darker 

 parent ; some of them run lighter than the less pigmented 

 parent. These parents also seem "pure dominants," 

 or, better, contain no hypostatic white. 



The significance of the data of these four families is 

 perfectly clear in view of the studies that we have made 

 on the inheritance of hair and skin color in "Caucas- 

 ians." There are many grades of pigmentation — more 

 or less definite stopping points, perhaps, in a continuous 

 pigmentation process. A tendency to proceed far in the 

 pigmentation process is dominant over the less progres- 

 sive condition, but imperfectly so. Consequently, first- 

 generation mulattoes are not as dark as the negro pa- 

 rent. Whether in the offspring of two such mulattoes 



