No. 545] ORIGIN OF UNIT CHARACTERS 



257 



Negro tribes in equatorial Africa has reached the follow- 

 ing- conclusions : 



There has been free intermigration ; in the course of their evolution, 

 the tendency of one tribe has been towards the accentuation of one set 

 of characters, of another towards another set. Thus the Dinka ac- 

 quire high stature and narrow heads; the typical Nigerians low stature 

 and narrow heads; the Basoko wide, short heads and low stature; the 

 Buruns wide heads and high stature. Interbreeding may have played 

 its part; but if it had played a great part we should have found 

 greater physical uniformity than there is. The influence of Arab blood 

 on these tribes has probably been exaggerated. 



It appears that environment has not any direct in- 

 fluence on head form, but that geographical isolation 

 affords the several varieties of man as well as other 

 mammals a chance to develop their peculiar head charac- 

 ters. Elliot Smith states (letter, August 12, 1911) : 



In my opinion the conditions of dolichocephaly and brachycephaly 

 must have developed very slowly through exceedingly long periods of 

 time and in widely separated areas amidst widely different environ- 

 ments. Brachycephaly is especially distinctive of the Central Asian 

 high plateau populations, dolichocephaly of the littoral and plain- 

 dwelling peoples; but these "unit characters" are now so fixed that 

 environment is powerless to modify them in a thousand years or so. 

 ... I do not believe for a moment in Boas [that is, in Boas's observa- 

 tions (1911) on the rapid influence of environment in modifying head 



Elliot Smith takes very strong ground as to the lack of 

 evidence that environment directly produces any modi- 

 fication of head form; he implies that such modification, 

 if natural, would only show itself after thousands oi 

 years of residence ; environment no doubt has indirect in- 

 fluence. Hrdlicka, on the other hand, has obtained defi- 

 nite results in the influence of environment on the vault 

 and face form of the Eskimo; 33 it remains to be shown 

 how far these changes are ontogenic. The recent con- 

 clusions of Boas (1911) 34 that dolichocephaly and brachy- 



- Hrdlicka, Ales, -Contribution to the Anthopology of Central and 

 Smith Sound Eskimo," Anthr. Paper Am. M. X. II., V, Pr. II. l'.M-., ,, - 

 "Boas, Franz, "The Mind of Primitive Man," 8vo, Macmillan Com- 



