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DOMESTIC RABBITS. C hap. IV 



become modified under domestication. No one will say, for 

 instance, that the occipital foramen, or the atlas, or the third 

 cervical vertebra is a part of slight importance. If the several 

 vertebrae of the wild and lop-eared rabbits, of which figures 

 have been given, had been found fossil, palaeontologists would 

 have declared without hesitation that they had belonged to 

 distinct species. 



The effects of the use and disuse of parts. —In the large lop-eared rabbits 

 the relative proportional lengths of the bones of the same leg, and of the 

 front and hind legs compared with each other, have remained nearly the same 

 as in the wild rabbit ; but in weight, the bones of the hind legs apparently 

 have not increased in due proportion with the front legs. The weight of 

 the whole body in the large rabbits examined by me was from twice to 

 twice and a half as great as that of the wild rabbit; and the weight of the 

 bones of the front and hind limbs taken together (excluding the feet on 

 account of the difficulty of perfectly cleaning so many small bones) has 

 increased in the large lop-eared rabbits in nearly the same proportion ■ con- 

 sequently in due proportion to the weight of body which they have to 

 support. If we take the length of the body as the standard of comparison, 

 the limbs of the large rabbits have not increased in length in due proportion 

 by one inch, or by one inch and a half. Again, if we take as the standard of 

 comparison the length of the skull, which, as we have before seen, has not 

 increased in length in due proportion to the length of body, tie limbs 

 will be found to be, proportionally with those of the wild rabbit, from half 

 to three-quarters of an inch too short. Hence, whatever standard of 

 comparison be taken, the limb-bones of the large lop-eared rabbits have 

 not increased in length, though they have in weight, in full proportion to 

 the other parts of the frame; and this, I presume, may be accounted for 

 by the inactive life which during many generations they have spent. Nor 

 has the scapula increased in length in due proportion to the increased 

 length of the body. 



The capacity of the osseous case of the brain is a more interesting 

 point, to which I was led to attend by finding, as previously stated, that 

 with all domesticated rabbits the length of the skull relatively to its breadth 

 has greatly increased in comparison with that of the wild rabbit. If we 

 had possessed a large number of domesticated rabbits of nearly the same 

 size with the wild rabbit, it would have been a simple task to have measured 

 and compared the capacities of their skulls. But this is not the case; 

 almost all the domestic breeds have larger bodies than wild rabbits, and the 

 lop-eared kinds are more than double their weight. As a small animal has 

 to exert its senses, intellect, and instincts equally with a large animal, we 

 ought not by any means to expect an animal twice or thrice as large as 

 another to have a brain of double or treble the size. 27 Now, after weighing 



27 See Prof. Owen's remarks on this &c.,' read before Brit. Association, 1862 : 

 subject in his paper on the ' Zoological with respect to Birds, see ' Proc. Zoolog. 

 Significance of the Brain, &c, of Man, Soc.,' Jan. 11th, 1848, p. 8. 



