MAMMALIA 



271 



is aquatic in habit, dwelling in holes along the banks of 

 streams. The brown rat (Mus dccumanus) has spread 

 from its original home in western China throughout the 

 whole civilized world. About 1730 it migrated into 

 Russia, appeared in Paris in 1750, was introduced into 



FIG. 307. Camel. Photographed in the Philadelphia Zoological Gardens. 



America along the Atlantic coast in 1775, and by 1850 

 had spread to the Pacific coast. It destroys young poultry, 

 eggs, and grain. Like the house mouse, it multiplies 

 rapidly, producing three or four litters annually of from 

 five to ten each. 



The hares and rabbits (Leporidce) are widely distributed. 

 The former have long ears and long legs, while in the latter 



