HOMOLOGIES OF TEETH. 371 



molar below, p 4, and not to that tooth, m i, which Cuvier regarded 

 as the lower homotype of the carnassial ; and, indeed, the more 

 backward position of the lower carnassial is so slight that its 

 significance might well be overlooked, more especially as the 

 two succeeding tubercular teeth above were opposed to two 

 similar tuberculars below. 



How unimportant size and shape are, and how significant 

 relative position is, in the determination of the homologies of teeth 

 as of other parts, may be learnt before quitting the natural order 

 of Carnivora ; e. g. by the condition of the dental system in the 

 Bear, ib. n. Ursus. Here the lower tooth, m i, instead of pre- 

 senting the carnassial character, and resembling iu form the 



O * ' 



upper tooth, p 4, which is the homologue of the upper carnassial in 

 the dog, has a tubercular crown, and corresponds in size as well as 

 shape with the upper tooth, m i, to which it is almost wholly op- 

 posed, and with the same slight advance of position which we 

 observe in the lower canine as compared with the upper one, and 

 in the four lower premolars, p i, p 2, p 3, p 4, as compared with 

 their veritable homotypes above. F. Cuvier divides the molar 

 series of the genus Ursus into c fausses molaires |-, carnassieres -- , 

 tuberculeuses -J^^J.' 1 The tendency in every thinker to gene* 

 ralise and to recognise Nature's harmonies, has led him here to 

 use the term ( carnassiere ' in an arbitrary sense, and to apply it to 

 a tooth above (IT. p 4), which he owns has such a shape and 

 diminished size as would have led him to regard it as merely a 

 false molar, but that the upper carnassial would then have en- 

 tirely disappeared; and it has also led him to give the name 

 ' carnassiere ' to a tooth below, m i, which he, nevertheless, de- 

 scribes as having a tubercular and not a trenchant crown. In 

 so natural a group as the true Carnivora, it was impossible to 

 overlook the homologues of the trenchant carnassials of the lion, 

 even when they had become tubercular in the omnivorous bear ; 

 and Cuvier, therefore, having determined and defined the teeth 

 so called in the feline genus, felt compelled to distinguish them 

 by the same names after they had lost their formal specific cha- 

 racter. And if, indeed, he had succeeded in discovering the 

 teeth which were truly answerable or homotypal in the upper 

 and lower jaws, the term ' carnassial' might have been retained 

 as an arbitrary one for such teeth, and have been applied to their 

 homologues in Man and other diphyodonts, where they are as 

 certainly determinate as in those aberrant Carnivores, in which 

 they have equally lost their sectorial shape. 



1 cxxi". p. 109. 



B B 2 



