1865.] JAMIESOKT— -LAST CHANUES IN' SCOTLAND. 191 



Chambers has remarked in his book just cited, although it would be 

 unsafe to lay much stress on this circumstance, seeing that we find 

 the same term occasionally applied to eminences similarly situated, 

 which we cannot suppose to have been surrounded by water. Megg- 

 inch, Inchmichael, and Inchture are all eminences in the Carse of 

 Gowrie, which would be insulated if the tide were to cover that 

 fertile plain. The term seems to be of less frequent occurrence in 

 the Carse of Forth, although there are many similar eminences in it. 

 The species of Mollusca, whose remains occur in these estuarine 

 beds, are all living at present, both in the seas of Britain, and also to 

 the south of this country, while some of them are not known to live 

 in the Arctic regions. The group is therefore different from that 

 found in the glacial beds, and seems to have more relations to the 

 south than to the north, indicating a climate, if anything, milder than 

 the present. (See Appendix, No. 5.) 



§ 7. Elevation op the Land to its present position. 



a. Beds of Peat and Blown Sand. — After the deep masses of 

 estuarine mud had been deposited at the mouth of the Tay, Forth, and 

 other rivers, together with the corresponding gravel-beds and 

 shingle-beaches along the coast, the land was elevated to its present 

 level. Whether this took place suddenly, or by a gradual impercep- 

 tible movement, we do not know, and of the date of the event we are 

 also ignorant. It has generally been supposed to have occurred 

 before the Eoman invasion ; but this is doubtful ; for Mr. Archibald 

 Geikie, a most intelligent and accomplished geologist, after having 

 made a special study of the question, has come to the opposite con- 

 clusion. I am unable to adduce anything new upon this point, and 

 shall therefore content myself with referring to Mr. Geikie's in- 

 teresting paper in the eighteenth volume of the Society's Journal, 

 where the subject is ably discussed. 



Although, therefore, we cannot tell exactly when the land at- 

 tained its present level, the time is evidently remote when the 

 extensive Carse district of the Forth was completely under water ; for 

 there seems to be no local tradition of such a state of things, and the 

 depth of peat-moss which we find on the top of this raised estuarine 

 mud at Blair-Drummond, and elsewhere, affords good evidence of a 

 supramarine condition having prevailed for many centuries. Mr. 

 Blackadder * tells us that this upper peat is from 8 to 14 feet deep 

 in some places, and that remains of large oak-trees occur at the 

 bottom of it, with their stumps rooted in the subjacent soil. These 

 trees, we are informed, often bear distinct impressions of the axe, 

 and a double row of the felled trunks have been laid to form a road 

 across the swamp. This wooden causeway now lies at the bottom of 

 the peat. The felling of the trees, and the construction of the road, 

 have been ascribed to the Eoman army under Severus, but I know not 

 on what authority — probably on little else than mere conjecture. Some 

 valuable tracts of Carse-soil have been reclaimed merely by clearing 

 off the superincumbent peat ; but large patches of it still remain. 

 * Wernerian Memoirs, vol. v. p. 424 (1824). 



VOL. XXI. — part i. p 



