THE WATER-RAT OR WATER-VOLE. 327 



munication which has for its end a purely social 

 object. 



SWIMMING. 



It is a curious fact that though swimming comes 

 naturally to the water-vole, while with the otter 

 it amounts purely to an accomplishment, yet the 

 water-vole never attains the complete mastery of 

 the water attained by the otter. At the best it 

 is but a poor swimmer, and compared with the 

 otter it is a weakling and a land-lubber. When an 

 otter is under water it swims with its whole body, 

 like a leech, propelling itself belly upwards or in 

 any other position convenience dictates ; but the 

 water-vole, on the other hand, swims like any other 

 rodent. When diving, it propels itself entirely by 

 its hind-paws, using its forepaws for groping its 

 way, grasping here a pebble, there a twig, and so 

 turning and steering its course with its forepaws, 

 while its hind-paws are used solely as paddles. 

 Some authorities state that the animal propels 

 itself with all four paws when diving in alarm, 

 but though I have repeatedly watched water-voles 

 most closely I have never seen the forepaws to 

 be used as paddles. Their function appears to be 

 limited exclusively to influencing the direction of 

 travel. 



Of course, there are obvious reasons why the 

 otter has attained a higher standard of perfection 

 in the water than has the water-vole ; for, quite 

 apart from the fact that the otter is a creature of 

 unusual gifts, it is dependent on its swimming- 

 powers for capturing its natural food ; that is, it 

 has to swim for its living, whereas the vole swims 

 merely for convenience and safety. The smaller 

 animal is in no way dependent upon its diving 



