CAENIVORA DIGESTIVE SYSTEM; 



381 



away. The canines, temporary and permanent, are very large, strong, conical, 

 and curved outwards and backwards ; the upper ones are the largest, and have 

 a space between them and the incisors, which 

 lodges the lower canines when the mouth is shut. 

 The molars, twelve in the upper, and fourteen 

 in the lower jaw, terminate in sharp projections ; 

 the last upper premolar and the first lower true 

 molar are the largest, and being furnished with 

 cutting edgss, they have been termed the sectorial 

 teeth, dens sectorius ("dent carnassiere" of 

 Cuvier). The other molars are slightly sectorial, 

 and also tuberculate — i.e., provided with pro- 

 cesses for crushing the food. 



The cat has only fourteen molars, eight above and six l?elow ; the other 

 teeth are like those of the dog, making up a total of thirty. The formula 

 probably is ;- 



Fio. 143. 

 Teeth of a Lion (CarnivoraX 



. 3-3 ^ 1-1 ^^ 3-3 



I. . c. — , p.m. , 



3-3' 1-1 -^ 2-2 



1-1 

 1-1 



= 30. 



The last upper premolar, and all the lower molar and premolar teeth may be 

 said to be sectorial in this animal. 



The oesophagus is very dilatable, and presents a well-marked infundibuli- 

 iorm union with the stomach. 



Fig. 144. 



Ctomach of a Dog -inflated, a, Cardiac por- 

 tion : b, Pyloric portion ; c, (Esophageal orifice ; 

 d. Duodenum. 



Fig. 145. 

 CsBCtun and colon of a Dog— inflated. 

 a, neum ; b, Caecum ; c, Colon. 



The stomach is simple and only slightly curved ; it is commonly described 

 as pear-shaped, resembling that of the horse, but with a very small and narrow 

 pyloric portion, terminating in a constricted valve. The mucous membrane is 

 all villous, the natural food of these animals requiring but little preparation. 



The intestines are short and small. The small intestine is suspended by a 

 mesentery ; its walls are thick. The colon is somewhat larger than the small 

 intestines, and divided, as in man, into ascending, transverse, and descending 

 portions ; the csecum is only a small, spiral appendix ; there is no floating 



