THE MOLE. 11 



making a shallow trench rather than a tunnel. Sometimes, as 

 in very dry weather, it is obliged to dive deeply into the earth 

 before it can find the worms, which detest drought, and cannot 

 exist but in damp situations. 



How marvellous is the amount of muscular power that is con- 

 centrated into so small a space. Every one who has worked at 

 digging a pit is well aware of the labour involved in his under- 

 taking, even with the aid of crowbar, pickaxe, and spade. If the 

 reader shotdd happen to have excavated a cubic yard of earth, he 

 will know by experience the amount of muscular exertion that 

 is required for the task, and will be the better able to appreciate 

 the tremendous powers of the Mole, which is able to drive its 

 tunnels so rapidly through the solid earth, and to throw up at 

 short intervals those well-known mole-hills, which contain as 

 much earth as would make a heap twelve feet in height and 

 twenty feet in diameter, were a man to be the workman instead 

 of the Mole. 



On looking over tjje list of burrowing mammalia, the observer 

 cannot but be struck with the wonderful manner in which they 

 emerge from the earth with unsoiled fur. This capability is the 

 more remarkable in the animal now under consideration, because 

 it is continually engaged in making new tunnels, and is not 

 content merely to pass up and down a passage already excavated. 

 The sides of the passages, which are popularly known as the 

 high roads, are by degrees worn quite smooth by the attrition of 

 the Mole's body, so that in them there is little danger of injurj- 

 accruing to the fur. But that an animal should be able to pass 

 unsoiled through earth of all textures is a really remarkable 

 phenomenon, which is partly to be explained by the character 

 of the hair, and partly by that of the skin. 



The hair of the Mole is notable for its velvety aspect, and its 

 want of " set." The tips of the hairs do not point in any par- 

 ticular direction, but may be pressed equally forwards or back- 

 wards or to either side. The microscope reveals the cause of 

 this peculiarity. The hair is extremely fine at its exit from the 

 skin, and gradually increases in thickness. When it has reached 

 its full width, it again diminishes. This alternation of tenuity 

 and thickness occurs several times in each hair, and gives the 

 peculiar velvet-like texture with which we are all so familiar. 

 There is scarcely any colouring matter in the slender portions of 



