222 ON THE NATIONAL CHARACTERISTICS OF SKULLS. 



marriage with other nations, will tend to produce a varying 

 type. These factors are both in operation in Europe. 

 Nations whose skulls have perhaps long ago been of a 

 well-marked distinctive character , are exposed to the same 

 environments and intermarry; the result is a confusion 

 and mingling of the two forms, one cropping up here and 

 another there. 



When Retzius made his observations there is no reason 

 to doubt that he was correct in the main ; nay, it is very 

 likely that his classification would still apply to the 

 majority of a nation's skulls ; but there is sufficient evi- 

 dence in these tracings to show that so numerous are the 

 exceptions, and so frequent the departures from one type, 

 that a classification founded on such a system is valueless. 

 It would be strange if it were otherwise. There is but 

 one species of man ; and however widely he may have varied 

 in some cases from the parent stock, when their varieties 

 become exposed to similar influences with others who have 

 remained unchanged, he would differ from all other ani- 

 mals if these distinctions did not diminish and finally 

 disappear. 



One other point is of interest. 



Progressive development always means greater inte- 

 gration and greater differentiation. The brain of the 

 Primates becomes constantly more unsymmetrical as it 

 becomes larger. In the Bosjesman, as in the Chimpanzee, 

 the convolutions are comparatively simple and symme- 

 trical. It is, to say the least of it, not improbable that 

 this increasing cerebral asymmetry will produce some effect 

 upon the bony cranium ; and hence it is not fanciful to 

 look upon this bilateral asymmetry, which is plainly seen 

 in many of these tracings, as evidence, cater is paribus, of 

 a higher type than would be afforded by a perfectly 

 symmetrical skull. 



Although the commingling of long-headed and short- 



