160 THE SCOTTISH NATURALIST 



horse-road, with its fodder and vegetable debris, suggested 

 that fungi the most common food of Limax maximus 

 might be actually growing in the mine. And as the result of 

 a first investigation our enthusiastic collector brought back 

 samples of fungus which he found growing primarily on the 

 pit props and spreading thence over the rock surfaces of the 

 excavation. The fungus, known to the miners as "damp," 

 was kindly examined by Professor J. W. H. Trail, of Aberdeen 

 University, who writes regarding it : " The fungus is certainly 

 a Polyporus. It is probably not quite normal in its develop- 

 ment, but I think it may be referred to P. destructor, Fr., 

 modified by its conditions of growth as regards form and 

 complete absence of colour." This is a common species, which 

 normally grows on stumps of trees and on the wood of Scotch 

 fir, larch, and willow. A species of slime-fungus, Strcmonitis 

 fit sea, discussed below, was also found on the pit props. 

 These growths no doubt supply the food material of the slugs. 

 As for the others, the intestines of the earthworms and of 

 the collembolan were filled with coal dust, from which pre- 

 sumably they extracted the organic matter derived from the 

 decay or breaking down of the fir logs. The spiders gave 

 evidence of faring sumptuously upon the flies which frequented 

 the workings, for their webs contained many wings and 

 remains of bodies. 



Lack of special -modifications. All the animals were 

 carefully examined in the hope that they might show 

 evidence of their peculiar habitat in modification of structure 

 or of colour. But none such were discovered. The colours 

 of all were as varied and as deep in tint as in specimens from 

 the open air, and in none were there any traces of reduction 

 in the size of the eyes. 



Introduction and establishment. Consideration of the 

 ordinary habits of the pit animals shows that the majority, 

 in at least one stage of their existence, are, or may be, 

 dwellers amongst wood, in damp, decaying portions, under 

 the bark, and so on. It is evident, therefore, that the greater 

 number have entered the pit along with the props which 

 support the roof and walls of the working. In the case under 

 investigation, these props were of Norwegian fir from which 



