264 WATER VOLE. 



although in time of snow it does not come abroad. 

 Five or six young are produced early in summer, 

 and deposited in a nest composed of dry grass and 

 other vegetable matters. This animal never makes 

 its appearance in houses ; nor is it injurious to man 

 otherwise than by perforating the banks of canals. 



I have seen an albino with yellowish-white hair 

 and pink eyes. But a more interesting variety is 

 that which I have described in the sixth volume of 

 the Transactions of the Wernerian Natural History 

 Society, under the name of Arvicola ater. It is 

 very common in some of the northern counties of 

 Scotland, where the Brown Water Vole is seldom 

 seen ; but it is also, although rarely, met with in the 

 southern districts, and in various parts of England. 

 At one time I felt pretty confident that this Black 

 Water Rat is specifically distinct from the Common 

 or Brown kind ; and even now I do not consider it 

 impossible that it may be so ; but the form, struc- 

 ture, proportions, and pile, are so similar, and the 

 skeletons present so little difference, that, until 

 better distinctive characters than I can point out 

 are obtained, it may be well to consider it merely 

 as a variety. 



On comparing skulls of both kinds I cannot de- 

 tect any remarkable difference, excepting such as 

 refer to size, for the Black kind is generally much 

 smaller than the Brown. Some individuals are 

 pure black, but others are blackish-brown, and all 

 intermediate tints are observed until we come to 

 Ihe ordinary colours, in a skeleton of the Black 



