062 



The Common Mole. 



iOct., 



the foundation of a wall, under a hedge, or at the root of a tree." 

 In the vast majority of cases, however, the fortress is placed 

 in the open field, and se^om in the situations indicated above, 

 although very occasion Ay the writer has found fortresses near 

 hedgebanks and under trees; in these instances the mole most 

 probably was not aware of the tree. Abundance of food, never- 

 theless, does influence him in his choice, in so far as being 

 satisfied with his locality, he encamps upon it. To imagine, 

 however, that a practically biind animal of the mole's impatient 

 disposition and subterranean habits can make a deliberate choice 

 of the most favourable spot after a survey of the surroundings, 

 is absurd. 



Everyone is familiar with the time-honoured figure of the plan 

 of the fortress. Originating from Geoffroy Saint-Hilaire and 

 elaborated by Blasius. it has been copied by every succeeding 

 writer without the slightest attempt at verification, until the 

 publication of the works of J. G. Millais.* and the late Major 

 Barrett-Hamilton. t The old text-books referred to this fortress 

 as though all were constructed exactly alike on a pre-arranged 

 plan of labyrinthine escapes from enemies above and below, 

 whereas observation shows that the more or less complicated 

 galleries are purely incidental in piling up a protecting heap 

 over the excavated nest ; there is one exception, however, which 

 will presently be described. 



The first act in the making of the fortress is the excavating 

 of the nest cavity at some point in one of the usual tunnels. 

 This cavity is spherical in shape and about the size of a man's 

 head, and is just below the surface of the ground. The earth 

 is ejected through a hole in the top in the same way as an 

 ordinary molehill is thrown up, viz., by forcing the earth ur> 

 with the top of the head in quick jerks. 



As the ejected earth piles up, the mole must penetrate the heap 

 and reach the surface, and in this way a tunnel is made. The- 

 nest cavity made, the next proceeding is to excavate the bolt run. 

 This is a tunnel leading downwards from the bottom of the nest 

 perpendicularly for some 6 inches, when it curves upwards and 

 opens into the original tunnel leading into the nest cavity. 



In order to protect the nest from enemies and weather, the 

 mole proceeds to pile up a huge mound of earth on the top of 

 the heap already over the nest, by further tunnelling outside 

 the nest. In the process tunnels are formed within the mound, 



* The Mammals of Great Britain and Ireland, 

 t A History of British Mammals. 



