such abundant and diversified remains of the animal world, yet has the latter series always, when penetrated, attracted the attention of philosophers to its appropriate suites of vegetable exuvia.*

The ancients, who were carefully observant of natural appearances, could not fail to become in some measure acquainted with the fossil remains of organic bodies-those "medals of creation," as the illustrious Bergmann has strikingly designated them. They were, however, sadly puzzled to account for their origin. Hence, they supposed the various lapides figurati, lapides idiomorphi, lapides qui figuram habent concha, cochleæ, &c., as they were cautiously called, to have had some equivocal seminal origin, and to have grown, during an anomalous sort of life, in the situations where they were found: while other and later writers referred the production of those organic fossils to a principle which they announced under such conveniently ambiguous terms as the vis plastica and the vis formativa. These theories were not merely applied to solve the knotty problem of animal reliquiæ, but also to account for those accumulations of bituminous wood which were so frequently discovered, and the striking dendritic forms of which were supposed to have arisen from tendencies to such formation inherent in the bitumen. Andrea

The organic remains of the coal formation are prodigiously numerous— especially of Plante. The list given by Mr. De la Beche, and comprising fossils from this formation in all parts of the world, exhibits the names of the following numbers of species; Euphorbiaceæ, 9. Conifera, 4. Doubtful Coniferæ, 10. Dicotyledonous plants of doubtful affinity, 20. Palme, 3. Canne, 1. Monocotyledons, of doubtful affinity, 14. Equisalaceæ, 15. Filices, 118. Lycopodiacea, 61. Plants of uncertain affinity, 42. Of animal remains the list presents, Pisces, 3. Mollusca, 14. Conchifera, 14. Among the latter are many marine remains which may perhaps belong rather to the strata alternating with the inferior rocks, than to the coal measures, in which, however, some of them have certainly been found.

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Mattiola, an eminent botanist, embraced the notion of Agricola, a German miner, who had written on the subject, that a certain "materia pinguis," or fatty matter, made to ferment by heat, gave birth to fossil organic shapes. Of this opinion was Fallopio of Padua, who not only conceived that petrified shells had been generated by fermentation in the spots where they are found, but gravely supposed that certain curious antique vases dug up at Monte Testaceo near Rome, were natural impressions stamped in the soil! Among the last supporters of the opinion of the generation of these organic bodies in the bowels of the earth, observes Mr. Parkinson, may be mentioned the celebrated Langius, who strenuously contended for their having thus obtained their forms and existence; Dr. Plott, who believed their figures to result from the operation of certain plastic powers with which certain saline bodies were endowed; and, lastly, Lhwyd, who combated the vis plastica of Plott, and supported the idea of their production from the semina of fishes, &c., raised with vapours from the sea, and conveyed, by the clouds and rain, through crevices or fissures into the internal parts of the earth. The more rational conjecture of Woodward, who attributed their situation to the effects of the general deluge, was rendered of less effect, in opposing these notions, from his having attributed to the waters of the deluge, an almost universal solvent power; by which, he supposed the rocks and mountains were melted down, and thus allowed the admission of these substances, not considering that by the same power, the organic bodies themselves would have been reduced to a mass not bearing their proper figures.*

* Parkinson, Org. Rem. I. 23.

Regarding the inflammable matter of our Coalfields as consisting chiefly, if not entirely, of accumulations of land vegetables once growing in the countries where they are now found embedded, and not as the transported reliques of a Flora of other climes; and finding in the proximate strata of shale, ironstone, or sandstone bodies, which, retain at least in the external traces of their original organic character configurations analagous to those of plants now only growing in tropical regions, scientific enquirers seem to be agreed in opinion, that, at the period when these plants flourished, the climate where they are now found must, to say nothing of other conditions, at least have been much hotter and moister than at present.

We may premise that, in examining these relics of a former world, whether in the mine, or as detached specimens, it is, necessary to decide carefully whether they be actual petrefactions, in other words organic matters penetrated and changed by the bituminising or lapidifying processes, or the mere infiltration of sand, clay, &c., into a cavity formed by the decay of the original body after the enveloping substance had hardened about it so as to form a mould, or only casts of such. The massive and often beautiful impressions of stems, raised from our coal mines occur in four different conditions; some consist of vegetables converted into carbonaceous clay, and still invested with their bark, reduced to the state of charcoal; others exhibit impressions of the same plant, with the surface entire, upon clay, slate, or sandstone; others are decorticated vegetables themselves; and, lastly, others are impressions of these decorticated plants.*

This view of the subject, first espoused by Mr. Steinhauer, has been very strikingly illustrated by a writer in "Loudon's Magazine of Natural History,"

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The subject of antediluvian botany has exercised the ingenuity of the shrewdest investigators of physical phenomena, both in our own country and the Continent, with the advantage that the fossil Floras of the coal formation in different places are remarkably similar. The naming and classification, however, of fossil specimens, exhibiting for the most part such varying and equivocal characteristics, and often such slight analogies to existing genera, must, it is obvious, be so difficult a task, that comparatively little of systematic harmony can be expected; and these difficulties increase as we descend from the comparatively recent to the more ancient deposits. Mr. John Phillips, of the York Museum (Professor of Geology in King's College, London), has, in the first part of his interesting "Illustrations of the Geology of Yorkshire," figured twenty species of monocotyledonous plants, as occurring in the coal associated with the liasic and oolitic beds about Whitby, and comprising specimens belonging to the kindred families lycopodina, equisetaceæ, filices, cycadeæ, and palmæ, of Sternberg; upon which he remarks that "the result of all accurate enquiries into the nature and distribution of fossil plants, is, that they consist of three great distinct groups of species, which occupy as many peculiar repositories in the series of secondary strata: one group lies above the chalk; (namely with the more recent lignites) another is included between the chalk and the lias (i. e. connected with the Whitby coal) and a third occupies the coal measures

(vol. viii. p. 34), where figures are given of the conditions of the stems of Sempervivum arboretum, Linn., in the progressive stages of decay.

* The great source whence our geologists have hitherto mainly drawn their knowledge of fossil plants, is the splendid work, the Flora der Vorwell of Count Sternberg.

and mountain limestone"-in other words, is associated with the more ancient carboniferous deposits. "A cursory observer," adds Mr. Phillips, "may, perhaps, be led to confound together the ferns and calamites of the coal district with the ferns and equiseta of the oolitic rocks: though to a botanical eye their difference is very apparent: but who can mistake the lepidodendra of the former, the cycadiform fronds of the middle period, and the dicotyledenous leaves and fruits which abound above the chalk ?"* As a specimen of a remarkable family of plants, the remains of which occur so extensively in the oolitic and liasic beds

Whitby. Cycas, a term applied by Theophrastus to a palm tree, is now used to distinguish a natural order of vegetables, introduced by botanists and phytologists as a connecting link between the ferns and the palms; they appear at the era of the Jura formation, which is regarded as the equivalent of the oolite rocks of English geologists, and seem to have borne an excessive relation to contemporaneous types, as compared with the present state of things. Brongniart is said to have obtained from the formation in question, seventeen species of fossil Cycadeæ, eleven

* Geol. Yorks. 155.

M.