206 The Scott is Ji Naturalist. 



the climate was cold and wet may be inferred from the following 

 facts : (i) The Carse-clays contain occasionally (but only rarely) 

 ice-floated erratics ; while the clays themselves have all the ap- 

 pearance of fluvio-glacial deposits. The sediment was probably 

 largely derived from the erosion of the Highland area by glacier- 

 ice. (2) When the Carse-beds are followed up the valleys they 

 pass into coarse river gravels, and these last in the Highland area 

 are associated with terminal moraines. At the time the Carse- 

 clays were being deposited, local glaciers existed in our Highland 

 glens. (3) The underlying forest-bed is largely made up of drifted 

 material. Trunks and sticks, etc., all bear evidence of having 

 been floated down the valley by river-action just when the Carse- 

 beds were beginning to accumulate. The whole appearance of 

 the drifted wood of the Tay and Forth valleys, and of the beds in 

 which it occurs, bespeaks the action of larger streams and rivers 

 than exist at the present day in these valleys. (4) Again, in the 

 interior of the country, the " buried forests " are covered with a 

 more or less thick sheet of peat — formed of marsh-loving plants. 

 In short, there would appear to have been a kind of relapse to 

 glacial conditions. During the preceding genial post-glacial epoch 

 perennial snows or ice fields seem to have been unknown in Scot- 

 land — at all events no trace of their former presence has been re- 

 cognized. Judging from the evidence supplied by the buried 

 trees, the raised-beaches, and so forth, one can hardly doubt that 

 the climate of what we may call the first forest-epoch of post-glacial 

 times was more genial and equable than that which we now en- 

 joy. And it is not less clearly proved that the climatic conditions 

 which supervened upon the close of that epoch were much colder 

 and wetter than those we experience at present. During the first 

 forest-epoch the British area was connected with the Continent ; 

 while the succeeding cold and humid epoch was ushered in, or 

 accompanied by the submergence of wide tracts in North-western 

 Europe, and by the gradual insulation of our lands. It was dur- 

 ing this latter epoch, as I have said, that the 45-50 ft. beach of 

 Scotland was formed. At that time Neolithic man lived upon our 

 coast-lands, his kitchen middens, being now met with ranged along 

 the line of the old sea margin. 



The cold and humid climatic conditions under which he lived, 

 eventually passed away, and were succeeded by drier and more 

 genial conditions, which once more favoured the extension of 



