8 INTRODUCTORY CHAPTER. 



such as oatmeal porridge, or bread made from any of the 

 cereals, but thrives best upon a mixed diet of vegetable and 

 animal substances ; and, indeed, the formation of his teeth is 

 such as to lead us to suppose that by nature he is intended 

 for it, as we shall hereafter find in discussing his anatomical 

 structure. 



VARIETIES OF THE DOG. 



The varieties of the dog are extremely numerous, and, indeed, 

 as they are apparently produced by crossing, which is still had 

 recourse to, there is scarcely any limit to the numbers which may 

 be described. It is a curious fact that large bitches frequently 

 take a fancy to dogs so small as to be incapable of breeding with 

 them ; and in any case, if left to themselves, the chances are very 

 great against their selecting mates of the same breed as them- 

 selves. The result is, that innumerable nondescripts are yearly 

 born, but as a certain number of breeds are described by writers 

 on the dog or defined by " dog-fanciers," these " mongrels," as 

 they are called from not belonging to them, are generally despised, 

 and, however useful they may be, the breed is not continued. 

 This, however, is not literally true, exceptions being made in 

 favour of certain sorts which have been improved by admixture 

 with others, such as the cross of the bulldog with the greyhound, 

 the foxhound with the Spanish pointer, the bulldog with the 

 terrier, &c, &c, all of which are now recognised and admitted 

 into the list of valuable breeds, and not only are not considered 

 mongrels, but, on the contrary, are prized above the original 

 strains from which they are descended. An attempt has been 

 made by M. F. Cuvier to arrange these varieties under three 

 primary divisions, which are founded upon the shape of the head 

 and the length of the jaws ; these being supposed by him to vary 



