78 PHYSICAL INVESTIGATION. [?ART I. 



always depends on the degree of resistance to external and in- 

 ternal influences possessed by various races. 



The shape of the cranium is now by many naturalists con- 

 sidered as an infallible criterion of race, and yet those who 

 have devoted the greatest attention to the subject admit that 

 the individual differences in the form of the cranium become 

 greater in proportion to the higher intellectual development of 

 a nation. 1 According to Engel, 2 there are but few deviations 

 in the cranial structure among uncultivated nations, but many 

 among civilized nations. We have already stated that this 

 fact is, with some exceptions, generally correct; and if we 

 repeat it here it is on account of the admission that the form 

 of the cranium is liable to changes. Though Edwards 3 is of 

 opinion that the effect of civilization amounts to very little as 

 regards its influence upon physical development, because 

 among the same people the most different degrees of culture 

 are found in connexion with the same physical type an axiom 

 which denies that mental capacities are indicated by the shape 

 of the cranium we must bear in mind that to support such an 

 opinion we would require a more exact division of national 

 types than we at present possess. We find, however, instances 

 which seem to prove that the form of the skull is by no means 

 as constant as is usually asserted. Eetzius, himself, found that 

 the female skulls belonging to the higher and middle classes in 

 Sweden are generally smaller than those of country people, 

 and he considers this to be the consequence of a different 

 mode of life and occupation. Latham 4 inserts a table from 

 Wilson's "Archaeology and Pre-historic Annals of Scotland," 

 in which it is shown that the cranial capacity of the ancient 

 Scots was less than at a later period, which he is inclined to 

 consider as the result of civilization. With regard to Negroes, 

 the old skulls of Negroes dug out in New York were, accord- 

 ing to Dr. Warren, much thicker, and betrayed, phrenologi- 

 cally considered, much less mental capacity than the skulls of 

 a recent date. 5 All this leads us to the view taken by Miiller 



1 Eetzius, loc. cit., p. 205, 1848. 4 " Man and his migrations," p. 63, 



2 " Unters iiber schadelformen," p. 121. 1851. 



3 Loc. cit., p. 30. 6 " Quarterly Review," June 1851. 



