212 Mr. Wood's Account of some Fossil Stems qf Trees. 



ing is much greater, but they seem all of the same character, proceed- 

 ing from the same bed of Shale, and the position nearly upright, or at 

 right angles to the line of stratification. All these were filled with 

 Sandstone, but some of them with a rather different kind than the one 

 presented ; but on following them a little way upwards, it was found 

 they were all filled with the same kind of Sandstone as that in which 

 they were embedded near the top. 



It is, perhaps, difficult to ascertain precisely to what genera or family 

 these fossil remains belong — the following conclusions seem to result 

 from these phenomena : — 



That on a comparison of the Fossil Stems and accompanying vegetable 

 impressions with living vegetables, they appear to be allied to those 

 existing in tropical regions of the south. 



That they have been plants of a reedy (^Jistulaire) nature, and conse- 

 quently inhabitants of a marshy soil, and that their hollow stems have 

 been filled by the deposition of the materials forming the rock in which 

 they are enveloped. This fact is proved by the sandstone composing 

 the filling matter containing very frequently impressions of leaves, or 

 the smaller vegetable remains, which is incompatible with the supposi- 

 tion of a substitution of silicious matter on the decay of a solid woody 

 substance, effected by infiltration. Besides, the termination of the top 

 of this Fossil Stem most distinctly proves its nature ; for it is impossible 

 to conceive that any other vegetable than that of a reedy nature could 

 be compressed so flat, and yet exhibit so perfect and unbroken an im- 

 pression of the original bark, or exterior surface. The plant most 

 nearly corresponding with all the appearances is of the class Sigillaria 

 of Brongniart, or Syringodendron of Sternberg. 



That these stems or vegetables have been inhabitants of, and have 

 lived in the place in which they are found. 



This is perhaps a conclusion to which we should approach with the 

 greatest caution, as furnishing evidence of a fact of the greatest impor- 

 tance to geology. The only supposition in contradiction to this fact is, 

 that they may have been drifted there, enveloped in the strata in which 

 they are found. When we consider, however, the manner in which the 

 roots penetrate strata of a quite different nature from that in which the 



