llie Scottish N'aturalist. 5 



From its association with the drifted trunks it is perhaps most 

 probable that it too was floated from a distance. It is not neces- 

 sary to suppose, however, that the water in which it sank was 

 deep. It is much more hkely that the canoe was stranded on a 

 low sandy beach, where eventually it became silted up. Indeed 

 it is not impossible that it may have been drawn up on the old 

 beach by its owners, and there abandoned. 



The clay is a somewhat tough, dark-greyish deposit, which 

 does not show any distinct lamination. In its lower portions it 

 here and there contains a good deal of vegetable debris. Higher 

 up, however, it is singularly free from such impurities. Now and 

 again one may detect in it a few small stones, which occur quite 

 sporadically. I have never met with any trace of shells in it. 



The overlying silt is a kind of loamy clay, of a darker colour 

 generally than the underlying deposit, but often hardly to be dis- 

 tinguished from it. It closely resembles the silt and loam which 

 are being now accumulated upon the flat shoals in the lower 

 reaches of the Tay. At Friarton it is only i foot thick, but in 

 other places it swells out to several yards. 



The highest terrace — that, namely, which has its upper limits 

 at 90 feet, or thereabouts, above the sea-level-— belongs to late 

 glacial times ; for as it is traced up the valley towards the 

 Grampians, it passes into kames and regular drift-gravels. I 

 believe it represents the upper limits reached by the enormous 

 torrents and floods that inundated the low grounds of Perthshire 

 during the final melting of the glaciers and snow-fields of the 

 last cold epoch of the glacial period proper. The same terrace 

 may be traced up the valley of the Earn. It gradually rises 

 to a height of nearly 200 feet, before it merges with the tumul- 

 tuous gravels at the foot of the mountains. 



When the deposits of the second terrace began to be laid 

 down, glacial conditions appear to have passed away. The 

 gravel and sand underlying the peat-bed resemble ordinary river- 

 accumulations, while the vegetation of the peat indicates a 

 climate not unlike that of our own day. It is quite clear, how- 

 ever, that when the plants of which that peat is largely com- 

 posed were growing, the land stood relatively to the sea at a 

 higher level than now, — but how much higher, the local evi- 

 dence hardly enables us to say. There can be no doubt, how- 

 ever, that the peat is of the same date as the similar accumula- 

 tions with buried trees that occur in many other places at and 

 below high-water along our coasts. It is extremely probable, 



