THE TEETH OF THE DOG. 



97 



UPPER VIEW OF WOLF'S SKULL. 



The great arches of bone beneath the eye are, in the Dog, nothing like so large as in the Cat, 



owing to the smaller size of the jaw muscles which pass under them. The snout, however, is much 



longer, in correspondence with the 



increased number of the teeth. 



There will be no difficulty in 



making out the teeth of the Dog 



now we have studied those of the 



Cat. We shall find, as before, that 



there are in the small front bones 



of the upper jaw three teeth on 



each side, and the same number in 



the corresponding part of the lower 



jaw : these are, of course, the inci- 

 sors. They are followed by the 



canines, or great eye teeth, of 



which, as in the Cat, there is one 



on each side of each jaw. After 



the canines, however, come no less 



than six teeth on each side of the 



upper jaw, and seven on each side 



of the lower. It is found that 



the first four of these are repre- 

 sented in the jaw of the young Dog 



by milk molars ; therefore, as we 



explained in treating of the teeth 



in the Cat, these four are pre- 

 molars, and the remaining three, molars. A likeness to what we find in the Cat exists in the fact 



that the last premolar of the upper jaw and the first molar of the lower jaw are very large teeth, and 



bite against one another. These are the carnassials of the respective jaws. Thus the dental formula 



of the Dog is incisors, |=j, canines, |=|, premolars, , molars, ?=? = 42. 



The form of the teeth, as well as 

 their number, comes much nearer to that 

 of an ordinary Mammal, or is much less 

 specially carnivorous than in the Cats. 

 The incisors are proportionally larger 

 than in our first section ; their crowns 

 are distinctly divided into three cusps 

 a large central and two small lateral 

 ones ; and the outermost incisors of the 

 upper jaw approach tolerably nearly in 

 shape and size to the canines, being 

 nearly half as long as the latter, and 

 having almost lost their lateral cusps. 

 The canines have much about the same 

 form and relative size as in the Cat, as 

 also have the premolars, except that the 

 first of these, though smaller than its 

 successor, is not so markedly so as 

 on the other 



UNDER VIEW OF WOLF'S SKULL. 



,, , , /,i ~,:i\ : , ^^^ollTr 



the last (the carnassial) is proportionally 



TEETH OF WOLF. 



The letters have the same significance as in the figure of the Lion's teeth on 



p. 13, except h, the "heel" of the lower carnassiai. 



larger. 



But in the molars, or at least in all but the lower carnassiai, we find something quite different, 

 namely, an interesting approximation to the semi-herbivorous type of dentition of the Bears. Both 

 62 



