42 HEREDITY OF SKIN COLOR IN NEGRO-WHITE CROSSES. 



Table 32. — Hair form in negro X white crosses. — Continued. 



(K) CURLY X KINKY. 



The observations made on form of hair were incidental, merely, 

 to those on skin color. They have, however, some interest as throwing 

 light on the question of the condition in the offspring of two parents 

 who belong to different types; also upon the question of segregation 

 of the types. This is a matter which was considered on a smaller 

 amount of data some years ago (G. C. and C. B. Davenport, 1908). 

 We reached the conclusion that hair form is inherited in typical fash- 

 ion; that two straight-haired parents have only straight-haired off- 

 spring; that two curly -haired parents will frequently have straight- 

 haired offspring; that waviness is a heterozygous condition, so that 

 two wavy-haired parents will have both straight-haired and curly- 

 haired offspring. 



The assertion has been made that a mixture of forms is found on 

 the heads of half-breeds, and Bond (1912) has described two such cases. 

 But Bond makes it clear that such mixture of hair forms is an excep- 

 tional phenomenon, as exceptional as spotted head-hair color in men. 

 Such a mixture of forms of hair was not found in our families, though 

 not particularly looked for except in about ten children. 



Fischer (1909, p. 1050) states that in the bastards of Rehoboth 

 the hair appears as a compromise between the Dutch and negro. It 

 is almost never entirely smooth, but almost never a close spiral, "pepper 

 com," hair like the Hottentots. It is of intermediate length, usually 

 has an open curl, or shows a narrow wave. 



Table 32 gives the results of all matings. Section A gives the 

 only cases where matings of two strictly straight-haired persons oc- 

 curred. The 7 progeny had straight hair. This accords with studies 

 made on whites. Straight is the recessive condition that does not 

 carry curvature. 



Section B includes straight by wavy, including some "slightly 

 wavy" and "ncariy straight" or "practically straight." Here there 

 are three prevailing forms, straight, wavy, and curly, occurring in the 

 proportions of 25, 22, and 19. On the hypothesis, supported by the 

 data of my earlier jjaper (1908, p. 344), that wavy is the heterozygous 

 or simplex form of curly, we might expect an equality of straight and 

 wavy in the offspring; but, as in the Caucasian material, curly does 



