150 MR WITHAM'S Description of a Fossil Tree 



by loose sand, or by sand mixed with water, would act all round 

 the stem, and so would not flatten it ; but if we suppose that the 

 tree in its recent state was carried along by a torrent of water 

 and sand, and left sticking as the latter consolidated, it would 

 afterwards begin to decay, when the hardened strata would ne- 

 cessarily press down upon it, and so produce the flattening ; and 

 those parts of the stem which decomposed rapidly, would natu- 

 rally shew the effect of pressure most ; and such may have been 

 the case with the fossil stem under consideration. 



In the great coal-field of the north, fossil plants are generally 

 found in a horizontal position, or parallel to the strata, in the 

 greatest possible confusion, much broken, much compressed, and 

 with their parts far separated. Indeed, the confusion is the most 

 serious difficulty the observer has to contend with. It is, how- 

 ever, by no means easy to trace the operation of a current of water 

 that has swept off weaker vegetables, and deposited them where 

 we now find them so beautifully preserved. 



Notwithstanding this, there are to be found in considerable 

 abundance, in various positions, large and strong trunks of plants 

 which appear to remain in their natural positions, and which have 

 been able to withstand the force of such torrents, if it can be 

 proved that any such existed. These vertical plants are general- 

 ly found to be Sigillarias. The Stigmariae of BRONGNIART (the 

 Lepidodendra of STERNBERG), and the Equisitaceas, on the con- 

 trary, do not appear to have been sufficiently strong to have re- 

 sisted such revolutionary influence. Several scientific gentlemen 

 having stated as their opinion that this fossil is a Lycopodium, I 

 may here mention the reasons why I have come to a different 

 conclusion. 1st, In this plant there are no appearances of inser- 

 tions of leaves on any part of it, or any markings similar to the 

 scales of Palms, or Ferns, or the imbricated leaves of the Lycopo- 

 dia. Judging alone from external appearances, the probability 

 is, that it is the stem of a dicotyledonous or gymnospermous 



