A SHOET EEVISIOX OF THE PAST VOLUMES 

 OF THIS SERIES. 



I DESIRE to say a few words here with regard to the whole of this 

 series, of which this is the tenth volume. 



In the earlier volumes, Buckley and I did not lay so 

 much emphasis upon what at the commencement we could only 

 look on as an experimental and somewhat new departure — viz. the 

 division of our whole area of Scotland into sub-areas and natural 

 divisions. Xor could we with any sense of security speak freely 

 regarding our views about migration, dispersal, and distribution, 

 because at that time these matters were — as indeed they still are in 

 great degree — dependent upon further developments and a larger 

 accumulation of facts. But we did realise, even at that early stage, 

 the necessity of starting upon a definite plan of work if these 

 desired accumulations of facts were ever to be easily used after- 

 wards. We therefore advocated 'natural faunal areas' instead of 

 ' political boundaries.' But we are willing to admit that before we 

 fully realised their importance, we carried out our idea somewhat 

 faultily — as has been exhibited especially in our first volume. In 

 some measure, perhaps, we have remedied this in subsequent volumes, 

 and our later appreciation may perhaps be illustrated by the volumes 

 upon the Moray Basin, and in the ninth volume, upon the North- 

 west Highlands antd Skye, where we went back to rectify the proper 

 positions of portions of Sutherland and West Cromarty, bringing 

 these into their proper faunal relationships. 



Further, I think that the apology which appears in the Preface 

 to the first volume for possible imperfections in observations by local 

 observers may be considered to be less in evidence in a.d. 1905, 

 because between 1887 and the present time the knowledge gener- 

 ally acquired has increased enormously ; and I think that the same 

 reproach can hardly be laid to their account for inability to obsers'e 



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