Manchester Memoirs, Vol. xlvii. (1903), No. 4 17 



about the tree at all ; however, the hollows among the 

 roots of old trees are sometimes utilised. Fig. 17 repre- 

 sents a fortress in the hollow trunk of a tree, which my 

 friend Mr. C. E. Wright discovered near Kettering. 



Abundance of food and water does influence the 

 mole in his choice of habitation more than anything else, 

 nor is this to be wondered at when we consider his 

 phenomenal voracity. But with regard to a deliberate 

 choice of " the most favourable spot " after a survey of 

 the cantonment by a practically blind animal of the 

 mole's impatient disposition and subterranean habits, 

 there can be no question as to its absurdity. 



The low-lying land about Aqualate Mere, Stafford- 

 shire, in which district I have excavated 109 fortresses 

 and breeding nests, is especially prolific in moles. In 

 damp weather, when the black peaty soil is moist, the runs 

 and galleries are very perfect and the whole structure is 

 easy to dissect, but in dry weather, when the soil is simply 

 black powder, the galleries fall in and the whole structure 

 is a homogeneous heap without galleries of any sort. 

 When these heaps begin to dry they are very often scored 

 by surface cracks radiating from the apex, which cracks 

 Saint-Hilaire supposed to be deliberately made by the 

 mole to drain off the rain ! 



I give illustrations of fortresses on boggy land, where 

 the nests were above the surface of the ground, in the 

 centre of the superincumbent heaps {Figs. 7 and 18). 

 Fig. 18 shows an interesting fortress on marshy ground 

 and liable to floods. The lower nest was made above 

 the surface of the ground with a shallow bolt-run. Then 

 came a flood and rendered this untenable. The mole 

 then made the second nest, with its accompanying runs, 

 on the top of the first nest. The dotted lines show the 

 fortress as it then appeared. Then came a second floods 



