182 DR BENNETT ON THE STRUCTURE OF THE 
tered through a substance often more than two feet deep, extending for acres, 
and it may be for miles. If these yellow masses be cells, what is their origin ? 
They cannot come from the woody tissue of the neighbouring coal, for, as 
we have endeavoured to show, such coal is destitute of them. The rings in 
coal are much smaller in diameter, are of regular size, and present the cha- 
racter of a tube cut transversely. Such rings could never be confounded with 
the yellow masses of the mineral. But supposing these latter to be cells, 
could such multitudes of them be derived from the gigantic ferns of the coal 
formation, or such as are imbedded in the mineral? I think not; because the 
amount of sealariform and woody tissue is too disproportioned to the number of 
the cells to favour such an idea. Besides, what kind of force or power could 
have been in operation that would have separated and collected the delicate 
cells, and left the ducts and other tissues of the plants by themselves, and out 
of sight, throughout such enormous masses. I have carefully examined the cells 
in large ferns, and observed the singular markings of cellular tissue, woody 
fibre, and scalariform ducts, many of them present, visible even to the naked 
eye,—than which nothing can be more unlike the Torbanehill mineral. The 
cells themselves are also larger, of more uniform size, and contain numerous 
starch granules; whilst the true resin cells are exceedingly large and distinct, 
strongly analogous, indeed, to what I have described as existing in the woody 
texture of coal, but wholly dissimilar to any thing observable in the Torbane- 
hill mineral. Such a view, indeed, would, it seems to me, lead to the extra- 
ordinary conclusion that this mineral is composed of a vegetable tissue, more 
cellular than any plant ever yet met with, recent or fossil, and so rich in cells as 
to be wholly dissimilar to what we can even imagine to have existed, taking its 
size and bulk into consideration. Such masses of cells could not have been formed 
or nourished without ducts passing through them in various definite directions, to 
convey a nutritive fluid; and yet we find such ducts only to be accidental, and only 
distinctly connected with plants imbedded here and there in the general mass. 
Whilst, then, the notion of these yellow masses being vegetable cells seems to 
me opposed to every known or conceivable fact yet ascertained to exist in vegetable 
histology, or from such as are demonstrable in the Torbanehill mineral, the theory 
of their being bituminoid masses imbedded in clay, appears to be in perfect har- 
mony with all of them, and especially answers the reasons given by Dr Reprern. 
With a view of determining whether the Torbanehill mineral could by any pos- 
sibility be produced by a process similar to that of the formation of peat, which was 
described at the last meeting of the Society by Dr Fiemrna,* I have examined vari- 
ous specimens of peat, and have confirmed his description. They consist of mosses, 
especially of the Sphagnum, the spiral cells of which plant are peculiar, and easily 
recognized, associated with broken-down woody tissue, root-stalks, and bundles 
* Proceedings of the Royal Society of Edinburgh, Session 1853-4, p, 216. 
