204 The Scottish Naturalist. 



baries we gather that forests of deciduous trees extended far 

 north of their present range, and reached elevations which the 

 same trees cannot now attain in these latitudes. Spitzbergen, the 

 Faeroe Islands, and Iceland have each preserved relics of this 

 genial post-glacial period. Nor is the evidence confined to our 

 peat-bogs and buried trees. Proofs of milder conditions having 

 obtained in early post-glacial times are afforded by the marine 

 organic remains of raised beaches, particularly by the shell-beds 

 of Norway and Spitzbergen, and by those of Nova Scotia and 

 New England on the other side of the Atlantic. And similar 

 evidence is supplied by the remarkable colonies of southern 

 forms that are met with now and again in northern seas. From 

 these and other phenomena it would appear that, in early post- 

 glacial times, warm water flowed in much larger volume than is 

 now the case into the arctic circle ; while the climate of North- 

 western Europe was certainly more genial than at present. 



The succeeding stage in the history of post-glacial times is, it 

 seems to me, not less strongly marked. Some twenty years ago, 

 after much wandering over the uplands of Southern Scotland, 

 which, as many of you know, abound in peat bogs, I got the 

 first glimpse of post-glacial climatic changes, and gave some ac- 

 count of my observations and conclusions ; which, however, failed 

 to attract the attention of British botanists. In succeeding years I 

 continued to investigate the matter, and was gratified to find that 

 a study of post-glacial fluviatile and marine alluvia exactly bore 

 out the conclusions which had already been suggested by the 

 phenomena of our peat. These conclusions may be briefly sum- 

 marised here ; as I would fain prevail upon some of our botanists 

 to take up the matter. The trees buried under the bogs proved, 

 as I then thought, and still believe, the former existence of con- 

 tinental conditions of climate for our area. But I held further that 

 the overlying peat was in itself evidence of changed climatic con- 

 ditions. It spoke of a wet, ungenial climate; and I associated 

 these conditions with the insulation of the British area. When I 

 began to study peat bogs it was, and may still be, the prevalent 

 belief that all the buried trees, or the major portion of them at 

 least, had been destroyed by man's hand. The overthrow of our 

 ancient woodlands was attributed partly to the Romans, and partly 

 to our " auld enemies of England." But I found that only a 

 small proportion of the forest-lands could have been displenished 



