272 



THE NATURE BOOK 



THE FORE-LIMB OF THE 



MOLE. 



"t Scapula. c, Radius. 



('. Humerus. <', Ulna. 



e, Sesamoid. 



that the internal structure of the ear is he has got his head and shoulders into 



so specialised as to compensate for the the ground he quickly disappears from 



absence of a conch. sight without leaving much debris be- 



The hillocks and surface runs, which Innd him. Sooner or later, however, his 



appear in pro- 

 fusion wher- 



e V e r Moles 



establish 



themselves, 



are jirobably 



familiar to 



many w h o 



have never 



had the op- 

 portunity of 



seeing either 



a Mole-for- 

 tress or a live 



Mole. There 



a r e several 



] problems i n 



c onnection 



with them 



which do not 



appear, as 



yet, to have 



been solved. 



Surface runs 

 will sometimes proceed for several yards 

 without any signs of a hillock, and with 

 only the arching of the soil, slightly 

 broken here and there by pressure from 

 below, to mark their direction. It is in 

 such runs as these, especially those 

 which lead towards water, or to the 

 shelter of some thicket, that it is easiest 

 to trap the Mole. At other times their 

 course is indicated by a succession of 

 hillocks whose combined bulk is out of 

 aU proportion to the disturbance of the 

 earth which mere tunnelling would entail. 

 It must be remembered in this con- 

 nection that a Mole works like a cyUn- 

 drical boring tool, and that he 

 employs his hands (as may be 

 seen from their imprints in stiff 

 soil) to compress the earth, 

 which he dislodges with his nose 

 and fingers, against the sides of 

 his tunnel. His progress, a suc- 

 cession of left and right twists 

 and thrusts (sometimes he screws 

 C()m]:)letely round so that he is 

 working on his back), may be vertical section through one side of a mole'S 

 compared to the act of bormg lower jaw, showing the structure of the 



a crowbar into soft soil. Once teeth and their roots /,v situ. 



the shoulder and arm bones of the 

 mole, with the corresponding bones 

 of the shrew mouse on the left 



FOR comparison. 



(I, Shoulder blade (scapula). '', Lower arm bones (Radius 

 /'. Collar bone (clavicle). and Ulna), 



c, Upper arm bone (Humerus), f, Hand. 

 e', Sesamoid. 



characteristic hillocks commence to ap- 

 pear. Mr. Adams holds, and I agree 

 with him, that in raising a hillock the 

 Mole is pushing up soil from below 

 with his nose. One is sometimes for- 

 tunate enough to see this rose-tipped 

 member while the hillock is in the mak- 

 ing ; more often, however, one can only 

 see the effect of it. The hillock rises in 

 jerks, often with considerable pauses 

 between them, the earth splitting up 

 the centre and cascading down the sides. 



