THE TEETH OF MAMMALS. 281 



A great deal of confusion has arisen out of the twofold 

 sense in which the word " canine " is used : if it were always 

 applied to designate the first tooth in the maxilla of the 

 typical mammalian dentition quite irrespective of its size, 

 <fec., and of the lower tooth closing in front of it, no objec- 

 tion to its employment could be made, inasmuch as it would 

 designate truly homological organs. 



But it so happens that the tooth in question is, in a very 

 large number of familiar animals, developed to a large size 

 and sharply pointed for use as a weapon, and so with the 

 word canine there comes to be associated a teleological 

 idea; and hence we are dissatisfied with calling the first 

 maxillary tooth "canine," when it is some other tooth 

 which is doing its work. 



On the other hand, if we are to leave out of court all 

 considerations as to size, purpose to which it is to be 

 applied, and so forth, there is nothing left to make it 

 deserving of a name distinguishing it from the four teeth 

 behind it. So we must be content with some such state- 

 ment as the following. 



A very large number of animals, notably the Carnivora, 

 have one tooth, situated a little way from the front of the 

 mouth, developed to an unusual length and sharply pointed, 

 for use as a weapon. The tooth which has undergone this 

 adaptive modification is usually the first which lies in the 

 maxillary bone ; in fact, the foremost of the premolar 

 series ; but it occasionally happens that it is some other 

 tooth which has undergone this modification. When we 

 use the term canine w r e should generally mean a tooth so 

 modified, and generally, but not always, should be alluding 

 to the same tooth, i.e., to the tooth which in the typical 

 mammalian dentition comes next behind the outermost or 

 incisor the first of the premolars, if we allow five premolars 

 instead of four. 



It would practically be very inconvenient to abolish the 



