CLASS MAMMALS : ORDER RODE^TIA. 



97 



House Mouse and the 

 House Rat (If. decu- 

 mamis), originally 

 from Central Asia, are 

 now found, through 

 transportation by 

 ships, in every part of 

 the world.* The rat's 

 tail is prehensile and 

 can be used as a 

 "hand, a balance, or 

 a projecting spring." 

 The Musk Rat lives 

 on the river bank and 

 in the water, using 

 its vertically-flattened 

 tail for sculling. Its 

 home is constructed 

 of reeds, with one 

 entrance above and 

 another below the 

 surface of the 

 water. 



G-eomyidae. The 

 Pouched Gopher is so 

 called from its curious, 

 hair-lined cheek- 

 pouches. These open '. 

 externally, and are ( 

 used for carrying out 

 sand from its burrow 

 and for taking in 

 food. 



Fig. 159. 



Hits musc&lus, Common Mouse. 

 Fig. 160. 



Fiber zibet/ileus, Musk Rat. 

 Fig. 161. 



G6&mys bitrsanus, Pouched Gopher 



* They are exceedingly cleanly and, in limited numbers, useful for their scavenger 

 work and destruction of insect venmin. When food fails they migrate in companies 

 to new places. In such journeys they often travel long distances and cross broad 

 rivers. They take with them the old and infirm, and Dr. Franklin asserts that he 

 once saw a rat leading a blind comrade by a twig grasped iu its mouth. 



