262 



THE AMERICAN NATURALIST [Vol. XLYI 



"cephaly of the Alpine type, recalling the broad-headed 

 Asiatic type of skull. Tims (Ripley, p. 56) "pure phys- 

 ical types come in contact and this means ultimately the 

 extinction of extremes." Applying these principles to 

 the present case, it implies the ultimate blending of the 

 long and the narrow heads and the substitution of one 

 of medium breadth. 



Elliot Smith also (letter, August 12, 1911) implies a 

 gradual modification or blending of head form through 

 prolonged intermixture. He observes: 



Egypt does not give a clear answer to your queries because her ex- 

 ceedingly doliei .. 1 face [related to the Mediterranean 

 race of southern Europe] underwent a double admixture (circa 

 3,000 B.C.) with moderately braehycephalic " Arnienoids " from Asia 

 and dolirli.HM-phalic NY-roes from Africa. The Mediterranean Egyp- 



years ago, and this may be due in part to a slow development toward 

 mesatieephaly; but it is mainly the result of an admixture with alien 

 bracephalics and m.-at icoplialio. There is an unquestionable tendency 

 toward the elimination of the extremes ot narrowheadedness and 

 broadheadedness. 



Hrdlicka (letter, December 5, 1911) observes: 

 As to the effect of the mixture of braehycephalic and dolichocephalic 

 individuals or peoples, I am led to believe that there is in the results 



distribution of the cephalic index among such national conglomerates 

 as the French, Germans, different tribes of the American Indians, etc. 

 These curves, if sutheientlv larye numbers of individuals have been ex- 

 amined, all approach more or less the ideal camel-back curve. If no 

 " blend " existed, we should be bound to get the double or dromedary- 

 back curve. Of course the effects of mixture and the effects of environ- 

 ment are with our present means often impossible of separation, they 

 often obscure each other. Yet the indications are that there is gener- 

 ally a considerable amount of more or less mixture of the many ele- 

 mentary constituents of the hereditary characters [known collectively 

 as] dolichocephaly and brachycephaly. . With this there coexists doubt- 

 less some tendency toward a differentiation into the two opposite forms 



Thus in human head form we have proofs of continuous 



