VARIATION AND HEREDITY 15 



color (red) does not completely dominate the other. In 

 this case the impure dominants show a color (pink) which 

 is a blend of the colors of the parental generation. 



This remarkable mode of inheritance has been dem- 

 onstrated to hold for a great diversity of organisms: 

 in mice, rats, rabbits, guinea pigs, cattle, poultry, 

 canaries, snails, silk-moths; in beans, maize, wheat, bar- 

 ley, and stocks. In cattle, for example, hornlessness is 

 the dominant and presence of horns the recessive char- 

 acter. In wheat, rough and red chaff are the dominant 

 and smooth and white chaff the recessive characters. 11 



Mendelian inheritance as applied to human characters 

 has not yet been worked out, if indeed inheritance of 

 human characters can be established at all in accordance 

 with this law. Dr. C. B. Davenport has found that when 

 both parents have pure blue eyes all of the children have 

 pure blue eyes; when one parent has pigmented iris 

 while the other has blue, either all the children will show 

 no blue eyes or else half of them will be blue-eyed ; when 

 both parents have brown iris either all the children will 

 have brown iris or else about a quarter will be blue- 

 eyed. 12 Professor Boas found that among Indian half- 

 bloods an extensive series of measurements of width of 

 face showed a decided tendency in the children to resem- 

 ble either the Indian race or the White race. The fea- 

 ture of Mendelian inheritance which brings about the 

 occurrence of mixed characters in the first hybrid gener- 

 ation was not found, but instead of this a decided ten- 

 dency of reversion to either type and a comparative rarity 

 of intermediate forms. 13 



11 Thomson & Gcddes, op. cit., p. 132. 



12 Davenport, C. B. Heredity in Relation to Eugenics, p. 31, 

 J3 Boas, F, The Mind of Primitive Man, 1911, p. 78. 



