158 Mr Bowman (m the Fossil Trees found on the Line of 



to have been originally hollow because we find them filled 

 with inorganic matter, were in reality solid timber trees. '^ 



I proceed, 2d, To shew that they have originally grown 

 and died on the spots where they are found interred, and 

 have not been drifte \ from distant lands. I have elsewhere 

 brought forward im^ ortant facts, which render it extremely 

 probable that coal ha s been formed from a vegetation which 

 grew on the areas nc \v occupied by the seams ; that each suc- 

 cessive race of plants vv^as gradually submerged beneath the 

 level of the water, and covered up by sediment, which accu- 

 mulated till it formed another dry surface for the growth of 

 another series of trees and plants; and that these submer- 

 gences and accumulations took place as manj times as there 

 are seams of coal. If this theory be true, it seems naturally 

 to follow that the trees also flourished on the same spots. 

 The advocates for the Drift theory account for the upright 

 position of fossil trunks, by supposing that the greater specific 

 gravity of their base would cause them to assume that posi- 

 tion when stranded, forgetting that when they touched the 

 bottom in shallow water, the current which had hitherto 

 borne them nearly upright, would lay them prostrate. We 

 must not forget that the fine smooth shale which usually en- 

 velopes the lower parts of these fossil trunks, could only have 

 been deposited from tranquil water ; the fine particles of 

 which it is composed would otherwise have been carried 

 away, so that this muddy sediment which surrounds them is 

 a strong proof of the absence of any current. Besides, it ge- 

 nerally happens that upright trunks are found upon, or a 

 little above, a seam of coal, whereas, had they been drifted, 

 the chances are equal that they would as often have been 



* I have tlie satisfaction of being enabled to state, that some recent in- 

 vestigations of Mons. Adolphe Brong-niart go very far to confirm the views 

 liere advanced. In a letter to myself, dated 21st March last, he says, 

 " What you tell me respecting your fossil trunks of Sigillaria is deeply in- 

 teresting, and very well agrees with what I have myself observed in a small 

 specimen of Sigillaria elegans, the internal structure of which has been 

 preserved. I have just ^escribed it in a memoir inserted in the first volume 

 of 'Archives du Museum d'Hist. Nat. de Paris,' in which I have endea- 

 voured to prove that it lias the nearest affinity in its internal structure to 

 the Cycadeae, which have essentially the organization of Dicotyledons." 



