A THEORY OF HEREDITY. 227 



of the head of the Keanderthal-Spy tj'pe. The occurrence of a football- 

 player of the Adriatic type so closely resembling the Neanderthal man, 

 indicates that the Adriatic type may be the nearest living related form 

 to this primitive precursor, the men of Krapina being intermediate 

 between the two. An additional factor favoring this view is the low 

 class standing of the Adriatic type, particularly of the football-player. 

 The Neanderthal skull is dolichocephalic, but Schwalbe has demon- 

 strated that the brain was brachycephalic. The enlargement and de- 

 velopment of the brain gives a brachycephalic head as is seen in the 

 Adriatic type. 



There is evidence, then, of a persistence of the riverdrift man of in- 

 terior Europe, represented primarily by the Neanderthal- Spy type, 

 secondarily at a later period by the men of Krapina, and at present 

 by the Adriatic, with some characteristics present in the Northern and 

 possibly in other types ; as well as a persistence of the Cave man of 

 Europe and the British Isles (Boyd Dawkins, Eskimo) in the Littoral, 

 and somewhat modified in other types. The Semitic, Iberian and Celt, 

 with their affiiuties in the types, are derived from other uncertain sources. 



When a single individual of any type is considered it should not be 

 supposed that the tjrpe is pure, but on the contrary, each individual may 

 have possibilities in the sex cells of any number of types, and the dif- 

 ferent sex cells have a different arrangement of the chromosomes so 

 that as frequently happens, there may be several types in one family, 

 esj)ecially if father and mother are of extremely different tj^es, when 

 the possibilities are greater. This may explain the appearance of Ibe- 

 rian, Alpine, Northern, Littoral and Blend Number 1 in one family of 

 my acquaintance, while in another there appears Celtic, Saxon, Littoral, 

 Alpine and Iberian, in the former the father being Iberian or North- 

 western (Littoral) and the mother Northern, and in the latter the 

 mother Iberian and the father Celtic. 



Individual characters are inherited in the same manner as these types, 

 when they are specific and separable, as in the case of the black and 

 white hair of guinea pigs, and Mendel's law ultimately works through 

 the law of chance in all heredity. 



It is to be noticed that none of the types are pure unless it be the 

 Celt, and even this may have obscure recessive characters. Only by 

 individual records of families followed for at least three generations can 

 the tendencies herein suggested be confirmed. Boas has shown that in 

 crossing long and short heads and wide and narrow faces (among Jews 

 and Indians) there is a tendency toward divergence in the offspring, 

 the more unlike the parents are; and the more nearly alike the parents, 

 the greater the tendency toward a blend of the two. Davenport and 

 Davenport have shown that the eje color follows Mendel's laws, dark 



