462 The Outline of Science 



attention. It is not only a bundle of adaptations, it is an 

 antiquity; it was long ago one of the discoverers of the under- 

 world; it ranges successfully from Mull to Japan; it lives an 

 unusually strenuous life; it has the charm of elusiveness and 

 idiosyncrasies. It has four modes of locomotion. Ordinarily it 

 "swims" deeply in the earth, using its hands to force the earth 

 to either side, and scratching backwards with its hind-feet. It 

 can burrow for a considerable distance without making a mole- 

 hill. Secondly, when there is food, e.g. leather- jackets (the larvae 

 of the crane-fly or daddy-long-legs), to be got near the surface, 

 the mole works along in a shallow groove, often breaking to the 

 open, and leaving a discernible track. In this shallow burrow- 

 ing, it uses its head and strong muscular neck a good deal, tossing 

 the earth upwards and to the side, in a way that recalls the old 

 name "moudie-warp" or "mould-tosser." Thirdly, it can run 

 about on the surface at the rate of about 2^/o miles an hour, and 

 the pairing takes place above ground. It must also be able to 

 trot along in those underground runs which have some per- 

 manence, e.g. the "bolt-run" from the headquarters. As to this 

 so-called "fortress," it consists of a roughly spherical nest about 

 the size of one's head, filled with leaves and grass. Above and 

 around this resting-place there is a mound made of the earth 

 which has been dug out, and traversing this there are tunnels 

 or galleries which were made in transporting the excavated earth 

 and may connect with the bolt-run or other radiating paths. No 

 two "fortresses" show the same plan of galleries; their symmetry 

 and significance have been exaggerated; they are simply the 

 necessary outcome of making a comfortable resting-place and 

 piling up the excavated material. According to some naturalists, 

 an elaborate "fortress" is made by the males only. The sexes 

 live apart, and the well-lined nest made by the female in May is 

 usually under an inconspicuous hillock. The young ones, usually 

 four or five in number, are pink and naked to start with, and 

 very helpless. But the development is unusually rapid, the 



