52 DESCRIPTION OF FOSSIL TREES DISCOVERED 



it in the usual manner, and was delighted to find that it presented traces of 

 its original structure. In March of the same year, I had the honour of 

 reading to the Natural History Society of Newcastle-upon-Tyne, an account 

 of my discovery, which was published in their Transactions. 



I was the more gratified by the discovery of a texture in the interior of 

 this fossil, as it afforded me an opportunity of corroborating the opinion of 

 so distinguished a botanist as M. A. Brongniart, who had inferred from 

 their external characters that the Lepidondendra were Lycopodiaceous plants. 

 To ascertain the correctness of his views, it became necessary for me to 

 examine the tissue of some recent species of that family, of which, however, 

 I could at the time procure only a single species. In so far as I have dis- 

 covered, the structure of that plant is analogous in most respects to that of 

 the stem presented by Mr Phillips. 



The specimens of the fossil plant in question seen by me, consist of sub- 

 cylindrical or slightly compressed dichotomous stems. The surface is cover- 

 ed by a thick envelope of carbonaceous matter, presenting indistinct pro- 

 tuberances, arranged in spiral series, and beneath which are observed pa- 

 pillae of an elliptical form, higher than broad. Plate XII. Fig. 1. repre- 

 sents a portion of one of the stems, denuded of its carbonaceous covering, 

 and of the natural size. 



Viewed in relation to its structure, the stem presents a central axis or 

 pith, which may be seen in the transverse section, Fig. 1, a, Plate XIII., 

 and in the longitudinal section Fig. 2. Plate XII. ; in the latter of which 

 it is entirely filled by calcareous spar, and a tube of carbonaceous matter. 

 This axis consists of a central portion, which, in the transverse section, pre- 

 sents rather an irregular cellular tissue, around which is a layer of cellular 

 tissue, of larger irregular polygonal cells ; and, lastly, a layer with very 

 small meshes. These appearances are seen in Plate XIII. Fig. 2, of which 

 a, b, b, represents the pith or central part ; and in Fig. 4. of the same plate, 

 where the tissue is better preserved. 



From the central column or axis, emanate on all sides, cylindrical pro- 

 cesses, consisting of cellular tissue, with central fasciculi of vessels. They 

 proceed obliquely upwards and outwards, as seen in Fig. 2, b, b, of Plate 



a 



