146 THE DESCENT OF MAN. Part I. 



brate series. Dr. J. Barnard Davis has proved 70 by 

 many careful measurements, that the mean internal 

 capacity of the skull in Europeans is 92*3 cubic inches ; 

 in Americans 87*5 ; in Asiatics 87*1 ; and in Australians 

 only 81*9 inches. Professor Broca 71 found that skulls 

 from graves in Paris of the nineteenth century, were 

 larger than those from vaults of the twelfth century, in 

 the proportion of 1484 to 1426 ; and Prichard is per- 

 suaded that the present inhabitants of Britain have 

 "much more capacious brain-cases" than the ancient 

 inhabitants. Nevertheless it must be admitted that 

 some skulls of very high antiquity, such as the famous 

 one of Neanderthal, are well developed and capacious. 

 With respect to the lower animals, M. E. Lartet, 72 by com- 

 paring the crania of tertiary and recent mammals, be- 

 longing to the same groups, has come to the remarkable 

 conclusion that the brain is generally larger and the 

 convolutions more complex in the more recent form. 

 On the other hand I have shewn 73 that the brains of 

 domestic rabbits are considerably reduced in bulk, in 

 comparison with those of the wild rabbit or hare ; and 

 this may be attributed to their having been closely con- 

 fined during many generations, so that they have exerted 

 but little their intellect, instincts, senses, and voluntary 

 movements. 



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 



70 ' Philosophical Transactions,' ] 869, p. 513. 



71 Quoted in C. Vogt's 'Lectures on Man,' En<r. translat. 1864, p. 

 88. 90. Prichard, ' Phys. Hist, of Mankind,' vol. i. 1838, p. 305. 



72 ' Comptes Eendus des Seances,' &c. June 1, 1868. 



73 ' The Variation of Animals and Plants under Domestication,' vo 

 i. p. 124-129. 



