66 LLOYD'S NATURAL HISTORY. 



found everywhere on the mainland, where suitable conditions 

 for its peculiar mode of life exist. The increase of cultivation 

 and of communication between remote districts will probably 

 account for this widening distribution of the Mole ; for it is 

 almost impossible to believe that its introduction into certain 

 districts can be due, as in the case of Mull, to accidental im- 

 portation by human agency. 



In Ireland, as already mentioned, the Mole is quite unknown. 



Geologically, the Mole is a comparatively ancient animal, 

 dating at least from the period of the so-called forest-bed of the 

 Norfolk coast, which is assigned by some geologists to the top 

 of the Pliocene, and by others to the base of the succeeding 

 Pleistocene epoch. 



Habits. Every writer who has described the organisation 

 and habits of the Mole has commented on the admirable 

 adaptation of the creature to the necessities of its surroundings. 

 Passing nearly the whole of its time beneath the ground, the 

 Mole leads an existence of continuous labour an existence to 

 our ideas which appears dull enough, but which nevertheless 

 may not be devoid of enjoyment of a certain kind. So swift 

 and rapid, when in suitable soil, are its subterranean move- 

 ments, that the creature has been not inaptly said to swim 

 through the earth. Such rapidity of movement through such 

 a resisting medium necessarily entails, however, an enormous 

 drain on the Mole's vital powers, to sustain which a vast and 

 almost continuous supply of food is essential to its well-being. 

 Hence even a very short period of deprivation of food speedily 

 results in death. 



As special instances ofadaptation we may note the following 

 structural peculiarities in the Mole. In the first place, the 

 cylindrical body, sharp muzzle, and short limbs, present the 

 least possible impediments to the creature's subterranean pro- 



