274 



THE NATURE BOOK 



the pressure of the spring which held one 

 side of the back in position, and the force 

 necessary was equivalent to the weight 

 of yh lbs., about thirty times that of 

 the Mole himself. The strength of the 

 Mole can best be realised b}^ holding 

 a full-grown one in one's hand and 

 allowing it to commence boring opera- 

 tions between one's fingers. I ha\'e 

 known a young Mole to accompany such 

 boring with a curious clicking noise. 

 I am inclined to think that the noise was 

 mechanical rather than vocal, though I 

 would not go so far as to suggest a ratchet 

 motion ! The voice of the young Mole is 

 a high-pitched squeak, and that of the 

 adult a squeal which is almost pig-like. 



I have, on more than one occasion, 

 resorted to my sense of touch to de- 

 termine the character of the boring by 

 which a Mole drives a surface run in 

 loose soil. I have accomplished this by 

 noting the direction in which a Mole is 

 travelling, and pushing a finger deep into 

 the ground to bar his progress. The first 

 sensation experienced is the screwing of 

 the Mole's nose. Then one feels the nose 

 slip forward and the claws of one hand 

 brought to bear with extraordinary force. 

 Finally one feels the Mole's teeth. It is 

 possible, of course, that the Mole may 

 mistake the finger for a prodigious worm, 

 but. from the nature of the cut which his 

 teeth inflict under these circumstances, 

 I think that progress rather than feed- 

 ing is in his mind. 



Every part of the Mole is modified to 

 suit the conditions under which he hves, 

 but his teeth, the bones of his shoulder 

 and arm, and his hair, present features 

 of peculiar interest. .\ Mole's hair is 

 almost identical with that of a Shrew 

 Mouse, and we will consider it in the 

 following article, noting now only the 

 peculiar difference of coloration wliich it 

 ])resents, accordingly as it is stroked from 

 head to tail or from tail to head. The 

 latter gives the rich characteristic black 

 velvet, the former a soft sheen of indigo. 



The shoulder and arm bones of the 

 Mole are of an extraordinary character, 

 and the bone of the ui)jKTarm {hiimcrits) is 

 one of the most aberrant bones known. 

 In the case of most animals (inchuling 

 ourselves) the humerus is typically " bone- 

 shaped." In the Mole, however, the 



humerus presents a form of which I think 

 my photographs will give a better idea 

 than any attempt at a description. The 

 collar bone {clavicle) is almost equally 

 peculiar, and the shoulder-blade (scapula) 

 presents an exceptionally long area for 

 the attachment of the great shoulder 

 muscles. The massive character and 

 interlocking of the two bones of the 

 fore-arm, and the modification of the 

 hand by the sickle-bone {sesamoid), which 

 makes an effective spade or fork of it, 

 according to the opening or closing of the 

 fingers, can be seen in the illustration. 

 Remembering that the massive character 

 of these bones is well matched by the 

 massive character of the muscles attached 

 to them, the reader will be able to realise 

 the immense strength which the Mole 

 can exert with his fore-limbs. 



The Mole possesses forty-four teeth, 

 and the points in which the molars differ 

 from those forms which we ha\-e already 

 considered can be easily seen in the 

 photographs. The back teeth of insec- 

 tivorous animals are pre-eminently well 

 adapted for deaUng with hard, slippery, 

 and wriggling material. A nip with two 

 ojiposing rows of them will pin any 

 creature which lies within their sphere 

 of action in twelve different points ; a bite 

 will cut it into twelve different pieces. 

 Thus a worm or insect is comminuted 

 rather than ground by the Mole's teeth, 

 and once the Mole has a grip of him his 

 fate is sealed. In eating an earth-worm 

 the Mole's evident intention is to trap a 

 considerable portion of it lengthways in 

 his mouth, and not across it. He bites, 

 like a Shrew Mouse, first with one side of 

 his jaws and then with the other. He 

 commences by holding the worm between 

 the in-turned sides of his hands, and 

 draws one end of it up between them 

 with his teeth, a process which no doubt 

 gets rid of much of the slime-coating. 

 The part of the worm between his 

 teeth and hands is stretched taut, while 

 the part beyond his hands wriggles 

 miserably. I have sometimes seen a 

 Mole make a series of little nijis along a 

 large worm before he attempted to eat it. 

 No doubt this action serves in some way 

 to crij)])le the worm, but the crippling 

 is not very obvious. 



Douglas English. 



