THE MOLE 



267 



contains not one, but two, three, and 

 even six nests (as was the case in one 

 vast mound, of which I give an ilhistration) 

 the pressure ot" the sui)erincumbent soil 

 becomes a serious matter, and I am 

 inchned to think that the Moles drive 

 arched galleries above the nests, primarily 

 to reheve this pressure, and, secondarily, 

 to secure some kind of drainage away 

 from the nests, and some kind of venti- 

 lation. The necessity for the latter will 

 be quickly realised by anyone who kee{)s 

 a ?.Iole closely confined. It is the repair 

 and maintenance of these galleries (I hax'c 

 found a gallery above the nest as polished 

 as a main run), and possibly also the con- 

 struction of fresh ones, which causes the ex- 

 ternal appearance of an established fortress 

 to alter appreciably from time to time. 



The reconstruction of a simple Mole- 

 fortress, of which I give an illustration. 

 was effected, so far as the abox-e-ground 

 portion was concerned, by means of 

 drawings to scale, of a series of vertical 

 sections at distances of one inch from 

 each other, commencing on the west side 

 of the mound. Horizontal sections were 

 made at the same intervals for the portion 

 below ground level, and both horizontal 

 and vertical sections were scaled to 

 fixed ordinates. The soil was in a suitable 

 condition for cutting, and I think that 

 the counterfeit may be regarded as 



■:?^"~-vCt 





apjiroximating fairly closely to the actu- 

 ality. It nnist, of course, be remembered 

 that the reconstruction is, in a sense, 

 negative, space being represented by 

 matter and matter by space. 



-.■^.i'^tjk 



Showing the nest-cavity, with nest in '.Hu. and an openinu 

 for removing the soil from the nest-cavit 



RECONSTRUCTION OF THE INTERIOR OF A 

 MOLE'S FORTRESS. 



The nest-cavity is represented by the rough sphere, 

 the tunnels by the surrounding ramification. 



The long diameter X to S of this mound 

 at ground level was about a yard, the 

 short diameter about twenty-seven inches, 

 the height about ten inches. These may 

 be considered as fair average dimensions 

 of fortresses in marshy ground. There 

 were eleven exits into the surrounding 

 soil, eight of which 

 can be seen in the 

 picture. These exits 

 were at depths rang- 

 ing from four inches 

 to eight inches below 

 ground level. There 

 were three entrances 

 to the nest, one at six 

 inches below ground 

 le\'el, the other two 

 at h\e. The top of 

 the nest-cavity was 

 about two inches 

 abo\-e ground level, 

 and the bottom about 

 six inches below. A 

 blind gallery described 

 a winding curve up- 

 wards from the nest- 

 cavity. Another l^lind 

 gallcrv. with a forked 

 ^in the tunnel used termination, lay 



