586 



ZOOLOGY. 



as a muskrat, is nocturnal in its habits and, therefore, rarely 

 seen, and burrows in the earth, feeding on roots. 



The lowest in intelligence are, perhaps, the hares, rep- 

 resented by the common varying hare (Lepus America- 

 nus Erxleben, Fig. 505), of which an interesting variety, 

 L. Bairdii, lives on the Alpine summits of the Rocky Moun- 



Fig. 506. The Spalax or Blind Rat. After Owen. 



tains. The largest of all existing rodents is the Capy- 

 bara of South America, which looks like a pig. This is 

 succeeded by the porcupine, which either lives in trees or 

 burrows in the earth, while the more intelligent, active 

 forms are the beaver, muskrat, the European blind rat 

 (Spalax, Fig. 506) the rats and mice, squirrels, and lastly 



the marmots. The domes- 

 tic mouse and the two rats, 

 the brown or Xorway rat 

 (Jfi/s decumanus Pallas), 

 the black rat (Mus rattus 

 Linn.), and the common 

 house mouse (Mus muscu- 

 Fi. SOT. Jumping Mouse (Zapus hud- ? Linn.), are cosmopoli- 

 tan animals. The jumping 



mouse (Fig. 507) has remarkably long hind legs and short 

 fore legs. Peculiar to the western plains is the prairie-dog, 

 {Cynomys ludovicianus) which represents the marmots of 

 the Old "World ; it is semi-social and takes in perforce as 

 boarders the owl and rattlesnake, which devour its young. 



