128 CLASS MAMMALIA. 



They are genuine plantigrades, and each foot has five 

 toes, remarkable for their thickness. The thumb of the 

 fore-extremities is visible only by the nail. The teats are 

 six in number. The two lower incisors are narrow, point- 

 ed, and developed, in separating from each other. The 

 molars are three on each side ; but it is unnecessary to enter 

 into any detailed account here of an animal so well known. 



The gait of the Rat is lively ; he runs with rapidity, and 

 makes very considerable leaps. Thus he often escapes 

 from his adversaries when attacked by open force. If he is 

 surprised, and obliged to defend himself, he does so with 

 courage, and often with success, by means of his long in- 

 cisors, which inflict deep and severe wounds. During the in- 

 tervals between eating and sleep, the Rat is constantly occu- 

 pied in cleaning and polishing his fur. He can carry his 

 aliments to his mouth with his hands, and drinks lapping. 



The Rat is usually about seven or eight inches in length. 



The next species worthy of a particular notice is theBrown 

 Rat, or Surmulot, before alluded to. On this we may remark, 

 that the introduction of a species into a climate that is new 

 to it is usually attended with great difficulties. Man, alone, 

 aided by his reason, can set his industry in opposition to the 

 inclement sky, and create a climate around him suitable to 

 his wants and wishes. But the habits and instincts of 

 animals are never sufficiently flexible to enable them to 

 supply new wants, and adapt themselves to new situations. 

 Unless they are under the especial protection of man, unless 

 his foresight comes to their assistance, they generally perish 

 after a struggle more or less protracted. Some, however, 

 are found which derive from our habits that which the 

 vigour of the climate would have refused them, and from 

 the influence of their constitution place themselves in the 

 very situation in which we would have placed them, had 

 we taken any interest in their preservation. 



Such is the case with the Surmulot, or Brown Rat, (Mus 



