the outside of the epidermis, nor were they at all visible on the remains of the soft part which had been in contact with it. Fig. 19. is a portion of the stem, or lignum, from which, when perfectly dry, its bark has been removed by peeling. It formed a hard and tough cylinder, of moderate thickness, the longitudinal striæ being only interrupted by the slightly elevated spots which held the spinous nerves as they emerged from the wood, and then passed through the bark, where they formed the external rugæ. That part of the bark which immediately covered the wood retained the same impressions on its surface, but that in contact with the epidermis had large tubercles corresponding with the outside of the plant; but in no case did this portion of the bark exhibit a pattern dissimilar from it.

In fossil plants it has been remarked that the same species may appear under three different states; such as are produced by the epidermal, cortical, and ligneous configurations: the first and the last differing much from each other; and, as Mr. Parkinson states, "it is only close observation that determines that it originates from the same plant."

Assuming that fossil succulent plants have undergone changes similar to those here represented, either before they were lodged in their matrix, or when so embedded, it will be easily perceived that one species may appear under several aspects difficult to determine. It is not improbable that, during the progress of maceration in the matrix, a variety of circumstances may have occurred to favour these changes and variations.

In contrasting these observations with what is visible in the submarine peat found in these islands, many indications point out a similar decomposition to be going on; and although these trees and vegetables have been buried many centuries, and are of a different description from those under notice, yet they exhibit changes nearly as difficult to recognise.

verru

còsus (fig. 20.),

"that this fossil was a plant of the succulent tribe, differing from vegetables of the present world by its containing a more solid part within its succulent substance, from which proceeded a delicate organisation, by which a communication was preserved with the external surface." He further adds: "It also appears that the species of this genus, distinguished by their characteristic markings, may have been numerous; that the different situations in which the internal part is found in different fossils are attributable to the resolution of the tenderly organised intermediate part, connecting the included substance with the surface, and to the other accidents dependent on partial and irregular decomposition, pressure, and distortion, occurring during its passage from the vegetable to the mineral kingdom."

M. Steinhauer has also remarked, in speaking of the Phytolithus cancellàtus (fig. 21.), "that the first or epidermal

description, which leaves the rhombs still approximate;" he again adds:-" In the ligneous, the cancellated appearance is here entirely lost, the surface is slightly striated, with a scarcely perceptible rising under the central ridge, and a minute but distinct raised dot in the place of the depression in the epidermis. It has all the appearance of a peeled plant, which had been furnished with small branches or spines in quincuncial order." M. Steinhauer also remarks," that these plants were furnished in the centre with a pith of a structure differing from the surrounding wood or cellular substance, more dense and distinct at the older end of the plant."

Comparing these statements with the appearance of the plants under review, a strong analogy will be observed between them, tending in some degree to elucidate this obscure subject, and bringing their variety of configurations nearer to our minds. It may be found interesting to those who have not examined the different states of the same plant while under decay, and may prevent the multiplying the number of species, whose only difference, perhaps, exists in the degrees of decomposition of the same plant.

Guernsey, January 8. 1833.

ART. X. A Notice of some important Geological Discoveries at Billesdon Coplow, Leicestershire; with Observations on the Nature of their Relation to the modern System of Geology. By JOSEPH HOLDSWORTH, Esq.

IN contemplating the numerous theories of the earth's structure and materials, which have from time to time been advanced by men of profound minds, one cannot but be struck with the discrepancy of those ideas and opinions which, like the ebullitions of fancy, have successively triumphed and radiated with an effulgent brightness, until the discovery of some new, some simple unexpected fact, some sad reality, has consigned them, in succession, to oblivion.

Much, very much, however, has undoubtedly been achieved; many luminous discoveries have been made, and many surprising truths have been established, by the meritorious exertions of the scientific, as is sufficiently exemplified in the modern system of geology. This system, however, notwithstanding it is countenanced by many of the most scientific characters of the age, may be far from the climax of perfection; and the warmest advocates of it even admit that it is liable to many weighty objections. Indeed, the complex, the multifarious, the extraordinary diversity everywhere observable in

the terraqueous arcana of nature, laugh at the poverty of our ideas, and mock the futile efforts of man to reduce them to system, or to effect anything approaching to a faithful delineation of so mighty, so mystical and magnificent a prototype.

Notwithstanding this, there are certain individuals who, in their anxiety to preserve inviolate adopted principles and preconceived notions, treat with disdain or levity such actual circumstances as do not happen to accord with their prepossessions, and thereby evince a disposition to give, rather than to receive, the laws of nature. Certain geological discoveries which I have recently made in this district, and of which a short account is published in Taylor's London and Edinburgh Philosophical Magazine and Journal of Science, vol. iii. p. 76. 112., 1833), have met with instances of this kind of reception; and on this account, as well as by the advice of some eminent literati who have examined the discoveries, I am induced to solicit the farther attention of the unprejudiced scientific to them and to their bearing on the existing system of geology.

This system originated in the labours of Mr. Wm. Smith, an English surveyor, who in 1790 published his Tabular Views of the British Strata; in which he proposed a classification of the secondary formations in the west of England, and contended that the order of different groups is never inverted, and that these groups may be identified at very distant points, by the presence within them of fossils of a determinate structure, peculiar to each. According to the order of superposition and marks of identification prescribed by Mr. Smith (admitting the infallibility of the latter in the present case), it appears, from the occurrence of the Grypha a incúrva and Pentacrinites Briàreus in the site of my trial for coal, that it is in the stratum which science denominates lias, and is situated about five miles from the eastern edge or extremity of the red marl. The last-named stratum, according to Mr. Smith's doctrine, reposes upon coal measures, and dips under the lias clays; consequently, if Mr. Smith's doctrine be true, and we assume the undisturbed presence of the above beds in this district, the lias and red marl formations must be penetrated before the old coal formation can be reached. The mean thickness of each of the two former strata is, according to the calculation of some geologists, about 500 ft.; the thickness varying extremely in different districts, even down to six or ten feet, and, in some cases, one or both of the beds are entirely wanting. At the Clutton Ridge pits, the red marl is, in some places, thirty fathoms deep, and in others but ten.

I will not stop here to question the correctness of the theory

which ascribes to every distinct stratum a new order of organic beings, nor dwell upon the unanticipated facts which my practical efforts have brought to light in this locality; but, in actual consistency with Mr. Smith's theory, I will proceed to adduce a few of the many instances which have occurred in this kingdom of the successful penetration, even from the surface of the oolite, to the carboniferous strata or independent coal formation. As instances: Paulton Hill, near High Littleton, Gloucestershire, is topped with oolite, beneath which is a bed of lias; then the newer red sandstone or marl, and finally the pennant or coal seams, at a moderate depth. In another part of the same county, the thickness of these beds, which lie above the coal, is as follows:- Oolite, 6 yards; lias 53 yards; red marl, 44 yards: in all, 103 yards to the coal formation. Coal is equally accessible through these formations near the Mendip Hills, and in some parts of Wales, &c. In the above districts, as in all others, .the various superstrata of the carboniferous formation vary much in thickness, in comparatively short distances. The Walton pit, a short distance east of Clutton, and near to Midsummer Norton, descends through the red ground, containing shaly limestone, in which fossils abound, and through the like order of mill grit, shale, and sandstone, to the depth of 200 fathoms, where the main bed of coal occurs. These instances sufficiently demonstrate the probability of the existence of coal in this place, at an obtainable or definite depth, especially when we take into account its proximity to the red marl and newly discovered coalfields to the west, and distant hence about fifteen miles in a direct line; and, additional to these considerations, we may reasonably calculate upon the latent existence, and consequent assistance, of some of those wise ordinations of Providence termed faults, by means of which the coal of very extensive fields is found to be, in many instances, thrown near the surface, when otherwise it would, in consequence of its natural dip, soon be out of the reach of the miner.

In the vicinity of these natural intersections (the consequences of subterranean convulsions), vast stratified masses, several miles square, are found to have been upheaved from very considerable depths. From among hundreds of instances of this case on record, I may here adduce two or three in illustration: - The coal formation of Ashby Wolds is a curiously denudated mass, entirely surrounded by the red marl, which (if it existed prior to the catastrophe) appears to have fled from its assigned geological destination, when the volcanic thunders shook the mineral treasures of its sub-neighbours, and summoned them to approach nearer to the light of heaven. The coal measures of