136 THE LIVING ANIMALS OF THE WORLD 



Photo by A. S, Rudland ftJ" Sont 



OCTODONT 



The octodont, so culled because they bai'e four molar teeth on each side of the jatv 



are a group of rodents found mainly in South America 



they often develop into a pest. The 

 Short-tailed Field-vole is respon 

 sible for much destruction of crops in 

 Europe. One of the latest plagues of 

 these animals took place in the Low- 

 lands of Scotland, where these voles 

 devoured all the higher pastures on 

 the hills. Nearly at the same time 

 a similar plague occurred in Turkish 

 Epirus. When a special commis- 

 sioner was sent to enquire into the 

 remedies (if any existed) there in 

 use, he found that the Turks were 

 importing hoi}- water from Mecca to 

 sprinkle on the fields affected. The 

 Bank-vole is a small English species, replaced on the Continent by the Southern Field-vole. 



The Water-rat belongs to the vole group. It is one of the most commonly seen of all 

 American mammals — probably, except the rabbit, the most familiar. Although not entirely 

 nocturnal, it prefers the darkness or twilight ; but whenever the visitor to the waterside keeps 

 still, the water-rats will allow him to watch them. The writer has had rather an extensive 

 acquaintance with these cousins of the beavers, and, while watching them, has never ceased to be 

 struck with their close resemblance to those creatures. At Holkham Lake, in Norfolk, he no- 

 ticed a willow-bush, in which a number of twigs had been gnawed off; and then saw the misMng 

 sticks lying neatly peeled, just like " beaver-wood," in the water below. Waiting quietly, he 

 noticed a water-rat climb into the bush, gnaw off a willow twig, descend with it to the edge of 

 the water, and there, sitting on some crossed boughs, peel and eat the bark, just as a beaver does. 

 By rivers a sound is often heard in the round reeds as of something tearing or biting them ; 

 it is made by the water-rats getting their supper. The rat cuts off three or four sedges and 

 makes a rough platform. It then cuts down a piece of one of the large round reeds full of pith, 

 and, holding it in its hands, seizes the bark with its teeth, and shreds it up the stem, peeling it 

 from end to end. This exposes the white pith, which the rat then eats. Water-rats have been 

 seen to swim out and pick up acacia blossoms float- 

 ing on the water. When swimming under water, each 

 hair is tipped by a little bubble, which makes the rat 

 look like quicksilver When it comes out, the rat 

 shakes itself with a kind of shiver, throwing all the 

 water off its coat. Though so good a swimmer, its 

 feet are not webbed. It is found from Scotland to 

 the Bering Sea, but not in Ireland. 



In the Far North the Lemming takes the place of 

 the voles. It is a very small, short-tailed creature, like 

 a diminutive prairie-dog. Like the voles, lemmings 

 have seasons of immoderate increase. They then 

 migrate in enormous flocks, and are said never to 

 stop till they reach the sea, into which they plunge. 

 It is believed that they are following an inherited 

 instinct, and that where there is now sea there once 

 was land, over which they passed onwards. 



The MuSK-RAT inhabits the same waters a- the 

 beaver of North America. It makes a house, generally 



\Korth Ftn.h'.er 



Photo by L. Midland, F.Z.S.] 



COYPU 



This is a large aquatic rodent, found on the South 

 American rivers. Its fur, called "nutria," forms a 

 •valuable export from Argentina 



