MARSUPIALIA. 89 



They are sluggish animals, with large flat heads, and bodies that look as 

 if they had been crushed. They are without a tail; have five nails on each 

 of the fore feet, and four, with a small tubercle, in place of a thumb, on each 

 of the hind ones, all very long and fit for digging. Their gait is excess- 

 ively slow. They have two long incisors in each jaw, almost similar to 

 those of the Rodentia; and each of their grinders has two transverse ridges. 



They feed on grass. One species only is known, the 



Phas. ursinus. (The Wombat.) Size of a badger; fur abundant, of a 

 more or less yellowish brown. It is found in King's Island to the south of 

 New Holland, where it lives in its burrow. Its flesh is excellent. 



ORDER V. 

 RODENTIA. 



We have just seen, in the Phalangers, canini so very small, that 

 we cannot consider them as such. The nutriment of these animals, 

 accordingly, is chiefly derived from the vegetable kingdom. Their 

 intestines are longj and the Kanguroos, which have no canini what- 

 ever, subsist upon vegetables only. The Phascolomys might stand 

 first in that series of animals of which we are about to speak, and 

 which have a system of mastication still less complete. 



Two large incisors in each jaw, separated frona the molars by an 

 empty space, cannot seize a living prey nor tear flesh; they cannot 

 even cut the food, but they serve to file, and by continued labour 

 to reduce, it into separate molecules, in a word to gnaw it; hence 

 the term Rodentia or Gnawers, which is applied to animals of this 

 order. It is thus that they successfully attack the hardest substances, 

 frequently feeding on wood and the bark of trees. The more easily 

 to accomplish this object, the incisors have no thick enamel except 

 in front, so that their posterior edges wearing away faster than the 

 anterior, they are always naturally sloped. Their prismatic form 

 causes them to grow from the root as fast as they wear away at the 

 edge; and this tendency to increase in length is so powerful, that if 

 one of them be lost or broken, its antagonist in the other jaw having 

 nothing to oppose or comminute, becomes developed to a most 

 monstrous extent. The lower jaw is articulated by a longitudinal 

 condyle, in such a way as to allow of no horizontal motion, except 

 from back to front, and vice versa, as is requisite for the action of 

 M 



