284 ORDER RTJMINANTIA ; GENERAL CHARACTERS. 



leaves and young shoots of trees or shrubs ; whilst the great pro- 

 portion have their mouths fitted for grazing upon the herbage 

 that covers the surface of the soil. 



253. All the animals of this order agree in the absence of 

 incisor teeth from the upper jaws, the hardened gum sustain- 

 ing the pressure of the lower incisors (which are apparently 

 eight in number) with their broad edges. Of these teeth, how- 

 ever, the two outer ones, which are usually smaller than the rest 

 and more oblique in their position, are really to be regarded as 

 canines, somewhat modified in their form ; this is evident in the 

 Camels, in which these teeth have the ordinary form and size 

 of canines. The molar teeth are six on either side of each jaw. 

 Their surface exhibits crescent-shaped ridges, formed by enamel 

 surrounding a centre of bony matter or cortical substance (ANIM. 

 PHYSIOL., 182). In the Camels, -there are apparently five 

 molars on each side ; but a sixth molar really exists, although 

 it is shaped like a canine tooth, and is placed immediately 

 behind the true canine, far in front of the other molars, so as to 

 resemble a second canine. The Camels are further remarkable 

 for possessing canine and incisor teeth in the upper jaw ; the 

 latter are originally four in number ; but the two central ones 

 fall out early, and those which remain resemble the canines in 

 figure. In the Musk-Deer, too, there are canines of considerable 

 length in the upper jaw, though the incisors are absent ; and the 

 presence of canines in the upper jaw is by no means un frequent 

 among the males of the ordinary Ruminants, their rudiments 

 being also discoverable in the female. 



254. The structure of the feet of the Ruminantia varies no 

 more than that of the teeth ; and where, as in the Camel tribe, 

 we find a departure from the usual type as to the latter, we may 

 notice it also in regard to the former. The feet are invariably 

 terminated by two toes, whose extremities are enveloped in 

 distinct hoofs; and the surfaces of these hoofs, which look 

 towards each other, are so flattened, that the appearance is that 

 of a single cleft hoof. Each toe has three phalangeal bones ; 

 and these are articulated with a single long metatarsal or canon- 

 bone. Besides the two large or true toes, there are two small 



