150 Proceedings of the Royal Physical Society. 



We have record of them, however, as early as 1844 in the 

 Forebank wood — Kinnaird, Brechin district — as I am in- 

 formed by the head gamekeeper to the Earl of Dalhousie. 

 We are thus able to trace their advance with some degree 

 of accuracy in this direction, and from evidence given under 

 Aberdeen, it appears likely that they came thus far before 

 entering Aberdeen. 



Aberdeen and Kincardine. 



In order rightly to understand the influx and increase and 

 spread of the squirrel in this county, it may be well if the 

 reader would consult the useful little map given in the first 

 volume of the Transactions of the Nat. Hist. Soc. of Aberdeen, 

 and the description of Deesideand Braemar which accompanies 

 it.* The author thus describes the district of Deeside, which 

 is marked 3 on this map: "The 3d district is sub-alpine 

 and alpine in character, and no part of it is under 600 feet 

 above the sea-level, while several of the hills exceed 4000 

 feet in height above the sea-level. It is characterised by 

 very extensive moors, with forests of birch and fir along the 

 slopes of the hills, and narrow strips of cultivation in the 

 glens. Here and there also — e.g., in Glen Callater, on Little 

 Craigandal, on Lochnagar, etc. — occur patches of alpine 

 flora, etc." 



Any one looking at this map of the natural divisions of 

 Dee, cannot fail to be struck with the precipitous nature of 

 the hills which surround the sources of the river — as indi- 

 cated by the narrowness of the river-basin ; and will 

 in great measure cease to wonder that the squirrel took a 

 long time to surmount such a barrier. The main avenues of 

 advance from Perthshire and Forfar are as follows : Through 



* " Sketch Map, showing the Divisions of ' Dee ' " {Trans. Nat. Hist. Soc, 

 Aberdeen, 1878, vol. i.). It becomes necessary to explain here the term 

 •' Dee," which can best be done in the author's own words. He says ; "In 

 the following lists I have restricted myself to the district between the basin of 

 the North Esk on the south, and the basin of the Spey (including the Deve- 

 ron) on the north and west. This tract was first defined as one of the zoolo- 

 gical provinces of Scotland, in the 'Scottish Naturalist ' (vol. i., p. 161) by the 

 name of 'Dee,' alike for brevity, and to distinguish it from the county of 

 Aberdeen, with which it is not equivalent " {op. cit., p. 24). 



