296 Mr. JVitham's Description of a Fossil Tree, 



would necessarily press down upon it, and so produce the flattening ; 

 and those parts of the stem which decomposed rapidly, would naturally 

 shew the effect of pressure most, and such I believe to 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 ob- 

 server has to contend with. It is, however, 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 generally found to be Sigillarice. The Stig- 

 marice of Brongniart (the Lepidodendra of Sternberg), and the 

 Equisetacece on the contrary, do not appear to have been sufficiently 

 strong, to have resisted such revolutionary infiuence. 



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. From external appearance. In this 

 plant there are no appearances of insertions of leaves on any part of it, 

 or any markings similar to the scales of Palms, or Ferns, or the imbri- 

 cated leaves of the Lycopodium. Judging alone from external appear- 

 ances, the probability is, that it is a stem of a Dicotyledonous, or Gymno- 

 spermous Phanerogamic plant. 2d. From internal structure. Having 

 examined, with care, the internal structure of this Fossil Tree, under 

 the microscope, agreeably to the rules laid down in my Observa- 

 tions upon Fossil Vegetation, I find it cannot belong to the former 

 of these classes. It has, however, most decided medullary rays and a 

 woody texture, with some appearance of concentric circles, and must 

 therefore belong to the order Coniferce. {See Plate XXV. Figs. 1 and 2.) 

 It cannot be a Cycas or a Zamia, and a Lycopodium it cannot possibly 



