144 ANNALS OF SCOTTISH NATURAL HISTORY 



to feed upon the corpses of their fellows hardly 

 warrants the assumption that Scottish voles in a 

 state of liberty will do the same ; and unless the 

 disease were communicable from one animal to the 

 other, it is not easy to see how the remedy could 

 prove effective on extensive hill pastures. 

 3. The fluid loses its value in about eight days after 

 preparation. Consequently much disappointment 

 might ensue if, after a supply had been obtained, a 

 fall of snow, or wet weather, were to interfere with 

 its distribution over the land. 



The remedy which has been found most effectual in 

 Thessaly is an injection of the fumes of bi-sulphide of carbon 

 into the burrows. This, however, is a more expensive process 

 than the other, besides being injurious to the health of those 

 engaged in its application. It is, moreover, inapplicable to 

 the Scottish vole (Arvicola agrestis], which does not burrow 

 to a depth like the vole of Thessaly (Arvicola Gilntheri}, but 

 lives in shallow runs amongst the roots of herbage. 



With the under-noted exceptions, the natural enemies of 

 the voles may be divided into two classes, viz. those which 

 destroy the voles, and are harmless to sheep, crops, and 

 game ; and those which, though preying on voles, are so hurt- 

 ful in other ways as to have no claim to preservation : 



i. Vole-killers, harmless, or ii. Vole-killers, hurtful in other 

 nearly so to sheep, crops, ways, 



and game. Foxes 



Owls of all sorts, Ravens, 



Buzzards, Carrion and Hooded Crows, 



Kestrels, and the Great Blackbacked Gulls, and 



Smaller Seagulls. Adders. 



Strict injunctions ought to be given by landowners that 

 the birds mentioned in the first class should not be destroyed. 

 Their presence in full numbers, though inadequate to avert 

 an outbreak, would undoubtedly tend to mitigate it, and, as 

 has been proved in the case of the short-eared owl, they have 

 the faculty of multiplying abnormally in presence of an 



