PETRIFIED TREES. 281 



confusedly intermingled. There are no erect 

 trunks, nor any other indications that the forest 

 was submerged with its native soil, like that of the 

 Isle of Portland.* On the contrary, this accu- 

 mulation of fossil trees resembles the rafts, as 

 they are termed, that are annually brought down 

 from the interior of the country by the tributary 

 streams of the great rivers of North America, and 

 which, hurried along by those vast floods, entangle 

 in their course the remains of animals and plants 

 that may happen to lie in the beds of the rivers, 

 or be floating in the waters. These rafts are at 

 length drifted out of the course of the currents, 

 and becoming loaded with mud, sand, and other 

 extraneous matter, sink down, and are engulphed 

 in the bed of the delta.-j- 



The fossil trees at Brook Point appear to have 

 been submerged when arrived at maturity, and 

 while fresh and vigorous ; for the trunks before 

 removed from the sandstone, are invariably covered 

 by the bark in the state of lignite. This cortical 

 investment quickly disappears when the stems 

 are exposed to the action of the waves ; but the 

 ligneous structure, which is converted into a very 

 hard calcareous stone, for a long while resists 



* Wonders of Geology, vol. i. p. 362. 

 t Ibid. vol. ii. p. 667. 



