Manchester Memoirs, Vol. x/v it. {igoT,), No. 4- 13 



Nearly every fortress has a bolt-run, by which the 

 mole can escape when surprised in the nest. This run 

 leads downwards from the bottom of the nest, and then 

 turns upward and out of the fortress by a tunnel of its 

 own and is very rarely connected with any of the other 

 numerous exits of the fortress. The only fortresses that 

 I have seen without the bolt-run have been on marshy 

 land, where such a tunnel would have led to water. 

 (See Figs. 7 and 1 3.) 



Occasionally one comes upon a downshaft, leading 

 directly from the nest downwards almost perpendicularly 

 for sometimes nearly three feet. The use of these 

 downshafts is puzzling. Where the land is low-lying 



Ftg. 15. — N. — Nest in marshy land. 



(J. —Downshaft, i8 inches deep measuring from bottom of 



nest, full of water when found. 

 ^. — Probable escape hole in flood. 



and the soil moist they may be intended to drain 

 the nest, but this is inconceivable in the Bunter sand- 

 stone on high ground above the level of the highest 

 floods, where I have found them on more than one 

 occasion. It has been stated that they are deliberately 

 sunk as wells to supply the mole with water, a notion 



