The Scottish Naturalist. 21 1 



our post-glacial accumulations, and the flora and fauna of our own 

 day, could not fail to throw much light upon the origin, character, 

 and distribution of the latter. 



Perhaps, I may be allowed to point out the kind of evidence 

 that geologists are in quest of. It is our belief that the low 

 grounds of Scotland were in early post-glacial times clothed with 

 an arctic-alpine flora, and you are well aware upon what inferences 

 that belief is founded. Hitherto, however, we have failed to 

 detect any relics of that flora in our post-glacial deposits. Such 

 remains, however, have been met with again and again, chiefly by 

 Dr. Nathorst, under the peat-bogs of the Continent. Now it can 

 hardly be doubted that, if our bogs were carefully examined by 

 botanists, similar discoveries would be made here. Special search 

 therefore should be made in the bottom layers of the peat and the 

 fresh-water clays which occasionally underlie our bogs. Then, a 

 ■careful examination of the trees underneath the peat is much to 

 be desired. The species and dimensions of the trees, the nature 

 of the soil, the position of the bog, and its elevation above the sea 

 should all be carefully noted. It should also be ascertained 

 whether the trees have fallen by man's hand or through natural 

 decay. The structure of the over-lying peat should likewise be 

 carefully determined. A mere list of the constituent plants will 

 not suffice. The observer must give a section of the bog — noting 

 the species and their relative abundance at particular levels. This, 

 I need hardly stop to remark, is essential \ for the succession of 

 plants, and the relative preponderance of certain species must 

 throw light upon the conditions under which the peat was accumu- 

 lated. The occurrence of trees or buried forests at successive 

 levels in the peat ought also to be carefully inquired into. Even 

 when no such trees are present in the middle of the peat, still we 

 may sometimes note a more or less definite layer characterised by 

 the apparent absence of sphagnum and its allies, and by the pre- 

 dominance of certain plants which indicate less humid conditions 

 than the true bog-forming mosses. Search should also be made 

 for animal organisms. I have often found the wing-cases of beetles 

 buried in peat, and now and again the remains of birds and small 

 mammals occur, as also human relics, and occasional traces of 

 former cultivation. 



Such are some of the points in which geologists are specially 

 interested ; and I earnestly hope that the naturalists of this Union 



