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small papillce, like tubercles ; but which, being sunk in the hollows, 
hardly ever rise above the general surface. A substance with a 
rough imbricated surface, and about one sixteenth of the thickness 
of the whole fossil, is frequently found passing through the centre of 
the cylinder, but more to the compressed side ; and frequently a 
sulcus, one edge of which rises into a sharpish ridge, may be 
observed to run in a line parallel with it. 
No conjecture, on which we can venture to rely, has yet been 
offered with respect to this fossil. The Arbor Lavendulce Foliis, 
Dr. Woodward says, hath studs, like these, and set in the same 
quincunx order. Mr. Whitehurst thinks it most resembles the re- 
mains of an Euphorbia, of the East Indies*. Indeed, there would 
be little difficulty in referring it, either to the genus Euphorbia, or 
to Cactus, were it not for the difficulty of explaining the nature of 
the internal substance. The surfaces, both internal and external, are 
frequently covered with a bituminous matter ; the interstice being 
closely filled with stony matter, which would dispose to the suspicion 
of their having been distinct vegetable bodies, which accident has 
thus united ; but, on the other hand, the frequency with which they 
are found connected, and the similarity of the mode in which they 
always appear to have been united, seem to point out that union to 
be natural, and not accidental. Dr. Woodward described this inter- 
nal body, in his earlier specimens, as a medulla or pith ; but after- 
wards, a more careful view of this body, he says, brought him to 
think it rather a commencement or beginning of a branch, arising 
out of the main trunkf . The data which we possess would almost 
lead to the supposition, that the plant, to which this fossil owes its 
origin, was of the succulent kind, which contained a more solid part 
in its succulent substance — ^but conjecture seems to be useless ; since 
* Inquiry into the Original State and Formation of the Earth, p. 208. 
f Catalogue of English Fossils, Part II. p. 60. 
