268 ANCIENT SEEDS. [BOOK n. 



extends about a mile along the middle of the valley, is about 

 ninety feet in thickness, and Mr. Kemp believes was formed 

 by the action of glaciers. It contains enormous angular 

 blocks of rock, and others smoothed and distinctly scored in 

 lines parallel to their longer axes. The layer of sandy clay, 

 on which the seeds rested, was capped by upwards of twenty- 

 five feet in thickness, of distinctly stratified sand, which has 

 been largely quarried. The beds of sand vary in thickness 

 and in fineness ; sometimes they alternate with thin seams of 

 impalpable clay, and sometimes they contain minute pebbles 

 and fragments of carbonaceous decayed wood. The layers 

 slope at an angle of fifteen degrees towards the valley, and in 

 this direction they thin out ; the upper layers extend further 

 into the valley than the lower ones ; the entire mass has a 

 level top, and is capped by some thin beds of fine gravel. 

 From these several facts, observes Mr. Kemp, and from the 

 general aspect of the layers of sand, it is scarcely possible to 

 doubt that the seeds were deposited by a river or torrent, at 

 the point where it entered a sheet of water. " I had long 

 been of opinion," he adds, " that the valley of the Tweed in 

 this part must formerly have been occupied by a lake, at a 

 period when a great trap dyke, 100 yards wide, which 

 crosses the valley four miles lower down at Old Melrose, had 

 not been worn through. By an accurate levelling I have 

 ascertained that the layers of sand lie just beneath that level 

 which a lake would hold if the barrier at Old Melrose were 

 reclosed. A depression on the surface of the land can also 

 be distinctly followed from the spot where the sand- quarry is 

 situated, up the valley, to where it joins the bed of the 

 existing river. I cannot doubt that the Tweed anciently 

 flowed in this depression, and deposited on the borders of the 

 lake the layers of sand where we now find them. It is 

 certain that in the time of the Romans, about 2000 years 

 since, no lake existed here ; and when we reflect on the time 

 necessary to have worn down the barrier of trap-rock and to 

 have drained so large a lake, which must have stood at its 

 highest level whilst the thin layers of sand were deposited 

 over the bed with the vegetable remains, the antiquity of 

 these seeds is truly astonishing, and it is most wonderful 



