54 



MAMMALS. 



Sub-family ARVICOLIN^, 



Arvicola amphibia {L.). Water Vole. 



Very often indeed is the black variety of this animal confused with the 

 true Black Rat — as already pointed out ; and often I have found it 

 no little trouble to sift the grain from the chaff. 



The brown and black varieties of this species are both well repre- 

 sented and fairly well balanced in their respective numbers and dis- 

 tribution, both as regards the actual proportions of their numbers 

 and the comparative dispersal. I am scarcely in a position to pro- 

 nounce any dictum. My own impression is that the black variety is 

 more abundant in the country north of our present area than it is 

 within it ; but this belief is subject to more minute investigation and 

 an increased number of specimens from a more extended series of 

 localities of records. There are other varieties in coloration, but 

 not of great importance, and there is also a difference in the density 

 of the pellage in individuals which may require looking into. 



Around Perth the black variety is usually found, but a white 

 (albino ?) specimen has obtained a resting - place in the Perth 

 Museum. 



Mr. J. Milne considers the species to be of less common occur- 

 rence around Auchenblae than formerly (at date of 1902), and at 

 Fordoun and on the Luther Water, but he does not assign any sup- 

 posed cause. 



Arvicola agrestis, De Selys, Common or Short-tailed Field Vole. 



This name, while descriptive and good, is, however, hardly an efficient 

 one, as has been pointed out by Mr. W. Evans {Mammals of Forth, 

 etc.) J if its numbers are to be compared with its nearest congener. 

 That is, A. glareolus is more strictly a lowland and woodland species 

 than A. agrestis, the latter being found even to the tops of our 

 highest mountains, as recorded by Mr. Bruce on the summit of Ben 

 Nevis in 1896 {Annals Scot. Nat. Hist., 1896, p. 187). 



1876 was the date of the historic Vole plague on our Borders. 

 Then followed 1883, and finally to date 1891, when the Board of 

 Agriculture reported upon the latter in 1892, and a Royal Commis- 

 sion went to Greece to investigate into its causes ! 



Of its distribution there is little to say except that it is almost 

 universal over the area, even going up, as already shown, to the 

 highest summits. Of its general distribution, it seems only neces- 



