ON THE TEETH OF MAMMALIA. 



123 



acutely projecting posterior angle of the jaw, and on a line drawn through 

 the teeth from the alveolar margin of the canine. 



The annexed sketches serve to illustrate this difference : fig. 126 is 

 the lower jaw of the Tiger ; fig. 127, the lower jaw of the Monkey : a, 

 the condyle ; 6, the coronoid process (into which the temporal and mas- 

 seter muscles are inserted) ; c, the posterior angle. 



126 



127 



Lower jaw of the Tiger. 



Lower jaw of the Monkey. 



In the Leopard, Tiger, &c., the distance from the condyle to the last 

 molar tooth is nearly as great as the distance from that molar to the ante- 

 rior face of the canine. The skull of a Leopard gives the following mea- 

 surement : from the posterior molar (its back part) to the condyle, two 

 inches and three-quarters ; from the posterior molar to the base of the 

 canine, anteriorly, three inches and a quarter. In the Wolf and Jackal, 

 the distance from the posterior molar to the canine is twice as great as 

 from the last molar to the condyle. In the Polecat, and other genuine 

 Mustelac, the respective admeasurements are almost the same as in the 

 Cat tribe ; the distance between the last molar and canine, however, being 

 somewhat more proportionately increased. In the Carnivora, then (and 

 especially in the feline race, the Hyaena, &c.), the great muscular force, 

 acting on the lower jaw as a lever, is thrown as far forward as pos- 

 sible ; for the space between the last molar and the condyle is occupied 

 by the coronoid process, which, to its very base, receives the insertion 

 of the crotaphite muscles ; and the more these muscles are carried for- 

 ward, the greater will be their effect upon the lever of the jaw. The 

 strain of this lever is referred to its point of articulation : hence its 

 peculiar construction, which, admitting of only one action, a simple 

 hinge-like movement, promises firmness and security. No semi-rota- 

 tory, or lateral motion, can take place in such an articulation; for the 

 transverse condyle is closely fitted into a corresponding cavity : in some 

 animals, as the Badger, the edges of this cavity advance, and enclose the 

 condyle, so as to lock it permanently up : therefore the lower jaw cannot 

 be separated from the skull, within the glenoid cavities of which its arti- 

 culating processes are solidly fastened. 



The characters of the trenchant molars of the true Carnivora, the 



