328 Descent and Upheaval over the Northern Hemisphere. 



be accounted for by the ponding back of the water ; it prevails 

 all around the shores of our islands and estuaries, penetrates 

 into the interior as far as the gravel or concrete beds them- 

 selves, and is visible on those portions of our shores exposed 

 to the full force of the ocean. It seems very probable that the 

 New Holland trees described by Mr Darwin, and perhaps the 

 Madeira wood mentioned by Dr M'Aulay, may belong to the 

 same class as the roots I have described, though I have not 

 felt warranted in adducing them as proofs of the hypothesis. 



10. I am satisfied that, to this variety of objects, the lignite 

 found near Cochin, in lat. 8° belongs, and that, were our 

 shores examined, it would be found at intervals everywhere 

 along them. In Scotland, at Perth, in the Carse of Gowrie,* 

 in the carses of Falkirk and Stirling, and under the present 

 city of Glasgow, and along the banks of the Clyde, boats and 

 canoes have been dug out from under ten to twenty feet 

 of alluvium, and still ten or twenty feet above the level 

 of high -water. Mr Chambers concludes from these things, 

 and, I think, most consistently, that the habitation of our 

 island took place before the last thirty or forty feet of its 

 elevation was gained from the ocean. May we not go fur- 

 ther than even this \ From the relations of these relics of 

 human art to the peat-beds and submerged forests around, 

 is it not possible that the depression under review was in 

 progress within the human period ? 



11. The absence of roots, in situ, is no proof of a depres- 

 sion never having occurred ; at the present moment, for 

 every fifty yards we have mangroves, we have at least 1000 

 where there are none, and on abrupt sandy or rocky shores, 

 wherever, indeed, the locality is unfavourable for the collec- 

 tion of mud and the growth of vegetables, we can have no 

 direct proof of depression. 



12. If, as I have shewn, we have the old sea-margin of 

 nearly uniform character, aspect, and elevation, presenting 

 itself everywhere, it is not surely too great a stretch of in- 

 ference to conclude that the depression was, like the upheaval, 

 not local, but general, and that the two everywhere followed 

 or accompanied each other. 



* Chambers' Old Sea-Margins, p. 19. 



