594 NATURAL HISTORY. 



causing any great diminution in their numbers. Plugging up their holes 

 is of no use, for they quickly dig others. 



We have various species of these gophers, but all are essentially the 

 same in habits. The species figured is the best known in the Mississippi 

 valley ; in our southern states, where the term ' gopher ' is applied, as we 

 have seen, to a turtle, the gopher is called a ' salamander ' ; why, is a 

 question more easy to ask than to answer. Other species occur on the 

 Pacific coast, and are there as great pests as are their relatives farther east. 



In South Africa, about the Cape of Good Hope, occurs the mole-rat. It 

 is rat-like in shape and about ten inches long, but has a short tail. It 

 occurs in immense numbers on the sandy beaches, excavating its tunnels 

 in every direction. In some places these forms are so abundant, and their 

 galleries are so numerous, that it is dangerous to ride on horseback along 

 the shore, so great are the chances of being thrown over the horse's head 

 by the unexpected sinking of the horse's feet into the holes, or by the 

 caving in of the burrows. 



The family which contains the true rats and their relatives is very 

 large, some three hundred species belonging to it; but of these only a few 

 need mentioning. One of the most important members of the group is 

 the muskrat of North America ; indeed, it is almost the only one that has 

 any great importance. In science it has been very fortunate, for it has 

 never been the recipient of many names. Of common names it has many 

 more, — musquash, ondatra, watsuss, wachusk, Massascus, and musk- 

 beaver. As this last name indicates, the animal shares to a certain extent 

 the habits of the beaver. This animal is so familiar that it needs but few 

 words. 



The muskrat is largely nocturnal in its habits. It prefers the marshy 

 1 tanks of rivers and ponds to make its home. It makes its summer resi- 

 dence in the banks ; but for winter it builds a hut in the water much like 

 that of the beaver, the entrance being below the surface. These huts are 

 constructed of twigs and mud, and may be from two to four feet in height. 

 Inside is a dry, warm nest lined with grass. In the winter they do not 

 become torpid, but are almost as lively as in summer. They leave their 

 houses, and make their journeys under the ice ; but as they are obliged to 

 breathe at intervals, they have their breathing-spots. These are covered 

 over with mud on the sides, and have a lot of loose grass in the centre, 

 which prevents the water from freezing except in the very coldest weather. 

 Muskrats are trapped in immense numbers for their skins, by means of the 

 ordinary steel trap baited with sweet apple, or some other favorite food. 



The lemmings are inhabitants of the regions around the north pole. 

 They occur in North America and Greenland, but the species of north- 



