36 HEREDITY IN RELATION TO EUGENICS 



If one parent has wavy hair while the other has straight 

 hair then, since in wavy haired persons half the germ cells 

 are without the determiner for curved hair, half of the off- 

 spring will have straight and half curved hair. If both 

 parents have wavy (simplex) hair about 75 per cent of the 

 children will have curved hair and the others straight hair. 

 But two curly haired parents, both of curly haired stock 

 on both sides, will probably have all curly or wavy haired 

 children. In a word, when either of the germ cells that 

 unite to form the fertilized egg contains the curly determiner 

 the offspring will have curved hair. 



4. Skin Color 



The pigment of the skin is due to brown granules lying 

 in the deep stratum of the skin. Such granules occur in 

 most people, are common in brunets and still more abundant 

 in negroes. Besides the brown granules a yellow-red pig- 

 ment is present, but this has been little studied. 



Now when both parents are clearly blonds most, if not 

 all, of their offspring are blonds. In 513 offspring reported 

 as derived from this sort of mating 91.4 per cent are recorded 

 as blonds and 6.8 per cent as intermediate, while only 1.8 

 per cent are stated to be brunet — quite within the limit of 

 error due to inaccuracy of the collaborators. If one person 

 is blond and the other darker, about half of the children 

 will, on the average, be blond and half pigmented but 

 rarely darker than the darker parent. If both parents 

 be dark the percentage of brunets ranges from about 25 

 to zero. In general, whatever the mating, the children will 

 not be darker than their darker parent. 



When one parent is white and the other as dark as a full- 

 blooded negro the offspring are, as is well known, of an 

 intermediate shade (mulatto, mezzotint). If two such 

 mulattoes marry their offspring vary in color. In one fra- 



