MANNER OF DEVELOPMENT. 53 



in Asiatics 87.1; and in Australians only 81.9 cubic inches. Pro- 

 fessor Broca™ found tliat the nineteenth century skulls from graves 

 in Paris were larger than those from vaults of the twelfth century, 

 in the proportion of 1484 to 1426; and that the increased size, as 

 ascertained by measurements, was exclusively in the frontal part 

 of the skull— the seat of the intellectual faculties. Prichard is 

 persuaded that the present inhabitants of Britain have "much 

 more capacious brain-cases" than the ancient inhabitants. Never- 

 theless, it must be admitted that some skulls of very high an- 

 tiquity, such as the famous one of Neanderthal, are well developed 

 and capacious. '^ With respect to the lower animals, M. E. Lartet,*'' 

 by comparing the crania of tertiary and recent mammals belong- 

 ing to the same groups, has come to the remarkable conclusion 

 that the brain is generally larger and the convolutions are more 

 complex in the more recent forms. On the other hand, I have 

 shown" that the brains of domestic rabbits are considerably reduc- 

 ed in bulk, in comparison with those of the wild rabbit or hare; 

 and this may be attributed to their having been closely confined 

 during many generations, so that they have exerted their intel- 

 lect, instincts, senses and voluntary movements but little. 



The gradually increasing weight of the brain and skull in man 

 must have influenced the development of the supporting spinal 

 column, more especially whilst he was becoming erect. As this 

 change of position was being brought about, the internal pressure 

 of the brain will also have influenced the form of the skull; for 

 many facts show how easily the skull is thus affected. Ethnolo- 

 gists believe that it is modified by the kind of cradle in which in- 

 fants sleep. Habitual spasms of the muscles, and a cicatrix from 

 a severe burn, have permanently modified the facial bones. In 

 young persons whose heads have become fixed either sideways or 

 backwards, owing to disease, one of the two eyes has changed its 

 position, and the shape of the skull has been altered apparently by 



s° 'Les Selections,' M. P. Broca, 'Revue d' Anthropologies,' 1873; see 

 also, as quoted in C. Vogt's 'Lectures on Man,' Bng. translat. 1864, pp. 

 88, 90. Prichard, 'Phys. Hist, of Mankind, vol. i. 1838, p. 306. 



=1 In the interesting- article juSt referred to, Prof. Broca has well 

 remarked, that in civilized nations, the averag-e capacity of the skull 

 must be lowerefl by the preservation of a. considerable number of 

 individuals, weak in mind and body, who would have been promptly 

 eliminated in the savage state. On the other hand, with savages, the 

 average includes only the more capable individuals, who have been 

 able to survive under extremely hard conditions of life. Broca thus 

 explains the otherwise inexplicable fact, that the mean capacity of the 

 skull of the ancient Troglodytes of Lozere is greater than that of mod- 

 ern Frenchmen. 



'2 'Comptes-rendus des Sciences,' &c., June 1, 1868. 



83 'The Variation of Animals and Plants under Domestication,' vol. 



i. pp. 124-129. 

 6 



