the Fossil Trees found at St. Helen's. 247 



of the stem remained, which at its base measured four feet 

 seven inphes in circumference. As in the large tree, the whole 

 of the bark was converted into coal, about one-third of an inch 

 thick, which fortunately adhered to the stem instead of the 

 matrix much better than in any of the other trees, and there- 

 fore showed the ribs and furrows of Sigillaria in a much more 

 perfect and distinct manner than the other individuals. This 

 tree, which was cylindrical in shape, was of a softer nature 

 than the others, being composed of the indurated gray silty 

 clay which constituted the matrix. Its base was a little conr- 

 cave, and from it sprung four slightly compressed roots, mea- 

 suring one foot six inches across at their origin. On the 

 under side of each root in the middle, appeared a singular su- 

 ture which ran under the base of the tree, and there uniting 

 formed a regular cross. The roots struck downwards almost 

 perpendicularly into the strata, and the whole tree bore great 

 resemblance to the molar teeth of a human being. The ex- 

 ternal surface of the roots was covered with a coaly envelope 

 much thinner than that which occurred upon the stem, and 

 was marked in a similar manner to the surfaces of the rootis 

 of the large plant, except that it showed the raised circular 

 markings of Stjgmaria and the diagonal depressions previously 

 alluded to running across their upper surfaces in a more pro- 

 minent degree. The roots all proceeded downwards to the 

 depth of about one foot six inches, tapering in thickness until 

 they came nearly to a point; afterwards they took a horizontal 

 direction, and could be traced as thin black flattened carbo- 

 naceous matter, sending forth radicles like those described pre- 

 viously in all directions, being in fact Stigmaria. In all re- 

 spects this stem and root and the stem and root of the large 

 individual already described resemble each other, except in 

 the number of the roots, appearing to be individuals of the 

 same species, differing only in age (see Plate V. fig. 2). 



No person, even on a casual view, could fail to be struck 

 with the great regularity and uniformity of the roots of the 

 larger tree when taken collectively. This great regularity re- 

 sulted from the spaces which intervened between each of the 

 roots, and which were of so uniform a nature that they could 

 scarce have been produced by accident. Of these spaces which 

 ran up to the base of the stem, there were four principal ones, 

 each resembling the other in size and form, and separated 

 from each other by the main roots, which were more than 

 three feet across. The boundaries of these intervals, which 

 were the sides of the main roots, gave them a rounded form 

 at their upper extremity, beneath which, at the distance of 

 about nine inches, they measured nearly a foot across. As 



