16 The Royal Society of Canada. 



a fire. The badgers often did what was compared to subsoil 

 ploughing. All the animals referred to were very active in the 

 autumn, digging many more burrows than appeared to be of any 

 use to themselves. Each hummock thrown up by the moles 

 covered about a square foot, and buried all the grass, etc., on this- 

 space. In this manner large quantities of vegetable matter were 

 ultimately incorporated with the soil. The work of the moles 

 also acted in another way, in refining the soil, for they left behind 

 the stones and coarse gravel, so that these in time became sunk 

 beneath the layer of mould produced. By a fortunate coinci- 

 dence, at the season when the bui rowing animals are most active^ 

 the prairie-vegetation is mature, and contains the largest amount 

 of useful substances. The coldness of the soil during the most of 

 the year tended to preserve the organic matter in it, while the 

 circumstances given were the direct cause of the fertility. The 

 ultimate reason was perhaps to be looked for in the climate of the 

 Northwest, for to this were due the growth of the vegetation which 

 formed the manure and the food of the little workers which 

 mingled it with the soil. Thus we could trace a mutual depend- 

 ence of the circumstances which together have given to our North- 

 west Territories that surpassing fertility of soil which cannot fail 

 to attract to it a vast population. 



The reading of this paper was followed by a very interesting 

 discussion. Dr. Selwyn corroborated what the author had said 

 as to the phenomena and their vast importance in an economic 

 point of view. 



Prof. Macoun considered that the chief cause of the fertility of 

 the soil was owing to the action of the frost on its rocky consti- 

 tuents, to which Dr. Bell replied that this did not account for the 

 introduction of the organic matter, and that on this the fertility 

 mainly depended. If the fertility were in proportion to the frost, 

 then the Arctic regions should have the richest soil, which was 

 not the case. 



Dr. Dawson mentioned that stratified superficial deposits were 

 found in various parts of the Northwest. The author said he had 

 referred to these in his paper as due to the transient action of 

 water during a submergence of the land, but that this was not a 

 material part of the question. 



In reply to a request, Professors Bell and Macoun described the 

 various burrowing animals which had been mentioned. 



