8 



THE NEW BOOK OF THE DOG. 



void their urine sideways, and lastly, like 

 our domestic favourites, however refined 

 and gentlemanly in other respects, they 

 cannot be broken of the habit of rolling on 

 carrion or on animals they have killed.* 



This last habit of the domestic dog is 

 one of the surviving traits of his wild 

 ancestry, which, like his habits of burying 



the St. Bernard and the miniature Black 

 and Tan Terrier, and is perplexed in con- 

 templating the possibility of their having 

 descended from a common progenitor. Yet 

 the disparity is no greater than that be- 

 tween the Shire horse and the Shetland 

 pony, the Shorthorn and the Kerry cattle, 

 or the Patagonian and the Pigmy ; and all 



SKELETON OF A RETRIEVER IN THE ROYAL COLLEGE OF VETERINARY SURGEONS. 



bones or superfluous food, and of turning 

 round and round on a carpet as if to make 

 a bed for himself before lying down, go 

 far towards connecting him in direct rela- 

 tionship with the wolf and the jackal. 



The great multitude of different breeds 

 of the dog and the vast differences in their 

 size, points, and general appearance are 

 facts which make it difficult to believe that 

 they could have had a common ancestry. 

 One thinks of the difference between the 

 Mastiff and the Japanese Spaniel, the 

 Deerhound and the fashionable Pomeranian, 



* Darwin: " Variations of Animals and Plants 

 under Domestication." 



dog breeders know how easy it is to produce 

 a variety in type and size by studied 

 selection. 



In order properly to understand this 

 question it is necessary first to consider 

 the identity of structure in the wolf and 

 the dog. This identity of structure may 

 best be studied in a comparison of the 

 osseous system, or skeletons, of the two 

 animals, which so closely resemble each 

 other that their transposition would not 

 easily be detected. 



The spine of the dog consists of seven 

 vertebrae in the neck, thirteen in the back, 

 seven in the loins, three sacral vertebrae, 



