No. 527] SKIN PIGMENTATION IN MAN 643 



unit. The anatomical differences between the skin of a 

 brunet and a blond suggest that the grades of color may 

 be due to more or fewer of the elements of the mosaic, 

 and that would seem to be a discontinuous variation; 

 but, on the other hand, since these granules increase in 

 size and number during melanogenesis the difference in 

 skin color between a negro, a mulatto, a brunet and a 

 blond may be merely a difference in the point at which 

 the essential melanogenetic process is stopped. 



Besides the melanic pigment a yellow-red pigment is 

 often present in skins of all races. This pigment is 

 commonly considered a lipochrome and, in hair at least, 

 is quite different in structure from melanic pigment. 



C. HEREDITY OF SKIN PIGMENT IN TYPICAL 

 CAUCASIANS 

 The data for the study of inheritance in ordinary skin 

 pigment of whites were obtained from two sets of in- 

 quiries. The first set was supplied chiefly by school 

 children on cards 127 mm. by 203 mm., which called also 

 for data on the form and color of hair and the color of 

 eyes. The second set was derived from the Family Rec- 

 ords filled out for over 300 families, largely by adult 

 persons, including many men in professional life, geneal- 

 ogists and students, as well as farmers and men of af- 

 fairs. 



The directions as to use of terms were necessarily 

 brief. In the first set they ran as follows: 1 '4. Natural 

 complexion or skin color. Use terms as follows: blond, 

 brunet, intermediate, yellowish-white, olive-yellow, dark 

 yellow-brown (dark olive), copper colored, chocolate, 

 sooty black, full black, three fourths black, one half black, 

 one fourth black." I willingly grant that terms are poor 

 means of expressing degrees and quality of skin pig- 

 ment. Nevertheless, blond and brunet are understood 

 widely in the same sense and it was hoped that "inter- 

 mediate" would be freely used in doubtful cases. This 

 expectation was not fully justified, since of 1,275 off- 

 spring recorded only 513, or 40 per cent, of all, were re- 



