98 NATURAL HISTORY. 



molars in the upper jaw, and the two last in tne lower, have become bond fide " grinders." The 

 scissor-like cutting edgs has disappeared, and in place of it we have a hard crushing surface, raised 

 into four cusps two large external and two smaller internal ones. This has relation, of course, to the 

 mixed character of the Dog's food. The sectorial molar of the lower jaw still, however, retains its 

 distinctive characters ; ite crown has much the same shape as in the Cat, but in addition possesses an 

 extra lobe, in the shape of a large heel-like process projecting from its hinder border, and formed by a 

 modification of its posterior cupp. 



The Dog family have, as a rule, longish legs. They walk on the tip of their toes, like the 



SltrLETON OF AYOLF. 



Cats; but unlike the latter, their claws are not retractile. Curious to relate, however, the elastic 

 ligament by which the drawing back of the feline claw is effected is present, but in so feeble a condition 

 as to be quite incapable of antagonising the great flexor muscles. 



In consequence of this, the paw of a Dog is by no means such a perfect weapon as that of a Cat; 

 and, as a matter of fact, the Dogs are distinguished from the Cats by their habit of always attacking 

 the prey at once with their teeth, and never beginning the attack with a blow of the paw. 



In the matter of internal anatomy, the Dog family differ from all other Carnivores in possessing a 

 large "blind gut," or caecum. The intestines, which are proportionally longer than a Cat's, are, as usual, 

 divided into large and small, and, at the place where the large and small intestines join one another, 

 there goes off a folded sac, communicating with the intestine at one end, but quite closed at the 

 other, forming, in fact, a small cul-de-sac. The use of this curious appendage is not properly under- 

 stood, nor why it should be so well developed in the Dog family, while it is very small indeed in Cats, 

 and wholly absent in Bears. 



!N"o member of this family attains the- size reached by some of the Felidce, such as the Lion and 

 Tiger, or some of the Ursidce, such as the Grizzly or Polar Bear ; the Mastiff is the largest of the tribe, 

 no wild species of which is larger than an ordinary Shepherd's Dog. 



THE DOMESTIC DOG.* 



We have now to consider an animal which has more interest for us than any member of the 

 animal kingdom, with the single exception of Homo sapiens; indeed, many people, if asked to name 

 the creature which feels for them the most disinterested friendship, the most devoted love, and which 



* Canis familiaris. 



