250 Messrs. E. W. Binney and R. Harkness's Account of 



roots of their creeping plant, but on the contrary, the concave 

 base froni whence the roots ought to have issued possessed si- 

 milar characters witli the radiating stems; and with regard to 

 the leaves, these appear to have radiated from the so-called 

 stems, not only striking upwards and sideways, but also down- 

 lioards, — rather an extraordinary direction for the leaves of a 

 creeping plant to take. Then as regards the supposed dome^ 

 shaped summit, which they state to be much damaged, they 

 do not appear to have looked after any portion of it in the 

 roof from whence the plant fell. Altogether these plants ap- 

 pear to have borne great resemblance to the base and roots of 

 the large tree at St. Helen's, which would most probably have 

 presented a perfect similarity, had the circumstances under 

 which it was first discovered been the same, viz. by excava- 

 thig under its base, when the lower portion would most pro- 

 bably have separated from the matrix, by one of the joints 

 which run through the plant from the strata, and have fallen 

 on the floor a perfect duplicate of the Jarrow fossil. 



Dr. Buckiand, in his Bridgewater Treatise, takes for granted 

 the dome-shaped summit, which was merely conjectured by 

 the authors of the Fossil Flora ; but the absence of large roots 

 appears to have been a difficulty, and he is led to trail in 

 swamps or float in shallow lakes his Stigmaria, " like the mo- 

 dern Stratiotes and Isoetes." Indeed, when we consider that 

 fossil botany has been termed the romance of natural history, 

 vve need not express any surprise at the numerous and vague 

 opinions which have floated along with this plant. 



Such are the two opinions which have been most currently 

 adopted, and which are still most generally entertained con- 

 cerning the nature of Stigmaria, which our description has 

 shown to be merely the root of Sigillaria. Perhaps it may be 

 urged that there is scarcely sufficient proof to show that the 

 larger tree was a Sigillaria, for although possessed of ribs and 

 furrows, it wanted the characteristic scars of this genus. These 

 scars are however in general obliterated near the base of all 

 large specimens, an effect the result of age, which also causes 

 several of the ribs, each of which is covered with a series of 

 scars, to unite and form themselves into one broad rib. These 

 gears also undergo considerable change in form as the plant 

 increases in age, first narrowing and lengthening considerably, 

 with only a small circular space in their centre covered with a 

 coaly envelope: this circular space gradually disappears as 

 the tree increases in size, and the elongated lines become less 

 distinct, and ultimately in old specimens all traces of it are 

 lost ; the large ribs themselves at the base becoming imperfect, 

 as seen in the large individual. 



