58 MAMMALIA. 



then follow one or two small teeth, that are perfectly flat. It is with these 

 small teeth in the back part of the mouth that the dog chews the grass he 

 sometimes swallows. We will call, with M. Fr. Cuvier, this large upper 

 molar, and its corresponding one below, carnivorous teeth ; the anterior 

 pointed ones, false molars ; and the posterior blunted ones, tuberculous teeth. 



It is easy to conceive that those genera which have the fewest false molars, 

 and whose jaws are the shortest, are those best adapted for biting. 



It is upon these differences that the genera can be most surely established. 

 It is necessary, however, that the consideration of the hind foot should be 

 added to them. Several genera, like those of the two preceding families, 

 in walking, or when they stand erect, place the whole 

 sole of the foot on the ground, a fact proved by the total 

 want of hair on that part of it. Others, and by far the 

 greater number, walk on the ends of the toes, by raising 

 up the tarsus. They are much swifter, and to this first 

 difference are added many others of habits, and even of internal conformation. 

 In both, the clavicle is a mere bony rudiment suspended in the muscles. The 



PLANTIGRADA 



Form this first tribe, in which the whole sole of the foot is placed on the 

 ground in walking, a circumstance which gives them a greater facility in 

 standing vertically upon their hinder feet They partake of the slowness 

 and nocturnal life of the Insectivora ; most of those that inhabit cold countries 

 pass the winter in a state of torpor. They all have five toes to each foot. 



Uasus, Linnceus. 



Bears have three large molars on each side in each jaw, 

 altogether tuberculous, and of which the posterior 

 upper, and the anterior lower, are the longest. They 

 are preceded by a tooth a little more trenchant, which 

 is one of the carnivorous teeth of this genus, and by a variable number of 

 very small false molars, which are sometimes shed at a very early period. 

 This almost frugivorous sort of dentition, is the reason why, notwithstanding 

 their great strength, they seldom eat flesh unless from necessity. 



They are large, stout-bodied animals, with thick limbs, and a very short 

 tail : the cartilage of the nose is elongated and moveable. They excavate dens 

 or construct huts, in which they pass the winter in a state of somnolency, 

 more or less profound, and without food. It is in these retreats that the 

 female brings forth her young. 



The species are not easily distinguished by apparent characters. We have 

 the 



U. Aretas L. (The European Brown Bear), which has the forehead 



