ground. On the other hand, Lindley and Hutton appear to consider them rather as the base or bottom of the stem whence the roots proceeded. Brongniart has appropriately named this fossil Calamites Steinhaueri, in commemoration of its original describer, an excellent man and ingenious Oryctologist.

The existence of antholithes, or fossilized flowers, has been generally doubted, on the ground that the succulent substance of the stamens and pistils must be too delicate to undergo the lapidifying or carbonising process: but there exist impressions on shale and sandstone in the British Museum, on viewing which it is difficult to resist the conviction that they exhibit some kind of stellate blossoms. That casts of seeds, ears of wheat, barley, or other of the cereal grasses occur in the true coal formation, has also been denied. Seeds, however, do sometimes occur but probably in no instance corn, notwithstanding the specious appearance of certain impressions to the contrary: indeed, it is asserted, that no trace of any glumaceous plant has been met with, even in the latest tertiary rocks, although we know that grasses now form a portion, and usually a very considerable one, of every Flora of the world, from New South Shetland to Melville Island inclusive.*

The remains of the animal kingdom found in the coal and associate beds are less striking than those of vegetable origin. Fossil fishes have been discovered in the carboniferous group, as well in Scotland as in this country-specimens from the coal in the neighbourhoods of Leeds and Newcastle being preserved in the Museums of both those towns. The large remains found in the ironstone of Wardie, and

Fossil Flora, I. xiii.

ANIMALS IN COAL STRATA.

107

in the coal fields of Greenside and Glasgow, and which were at first considered to be remains of saurian animals, are now determined by M. Agassiz and other Ichthyologists, to be true fishes.

About the middle of the coal series in Derbyshire, or in the ninth bed of shale, reckoning in the ascending order, a stratum of ironstone occurs, which is so full of different species of Mytili, &c. as to be distinguished by the name of the muscle band. There have been instances mentioned by various authorities of living toads found incarcerated in the coal strata: the fact of there ever having been in reality any such discoveries, is denied by Professor Buckland, who attributes the reports to mistakes on the part of pitmen, who having met with the animals in their workings, imagined them to have been dug out of the coal, without considering that they might but recently have entered the shaft. However this be, and the supposition is more facile than sound, the learned

In the brown coal formation, which belongs to a more recent geological era than the true carboniferous group, animal remains are frequently found, especially in the lignitic deposits of the European continent. Mr. Lyell mentions that many entire jaws and other bones of an extinct mammifer, called by Cuvier Anthracotherium, have been found in the coal beds of Cadibone, the bone being itself changed into a kind of coal. In these beds, however, although comprising carbonaceous shales, and several seams of coal from two to six feet in thickness, no shells have been discovered, nor impressions of plants of which the species can be determined. The same authority also informs us, that near the valley of the Rhine, a tertiary formation, called brown coal, from the association with it of beds of lignite worked for fuel, contains various organic remains, particularly fishes and frogs: they are found in a bituminous shale, called paper coal, from being divisible into extremely thin leaves. It may be mentioned here, as an interesting distinction of the two groups, that while the vegetable matter which has been changed into the common coal, was until recently considered to have belonged exclusively to monocotyledonous plants of extinct species, all the distinguishable remains of plants in the lignite and associated beds are said to belong to dicotyledonous trees and shrubs, bearing a close resemblance to those now existing in the country.

Professor's experiment shewing that toads died when confined without air or food in closely glazed stone cells, no more disproves the repeatedly alleged discovery of live toads in coal, than it does their extraction from blocks of marble, of which latter fact, at least, there does not appear to be any reasonable doubt.*

In concluding this chapter, it may be interesting to mention that, at the beginning of 1833, some "Observations on Coal" were read before the Philosophical Society of Newcastle, by W. Hutton, Esq., from which it appeared that, on examining with the microscope one of those slices of coal in which Mr. Witham had discovered a distinct vegetable texture, the attention of the Author was excited by the remarkable appearance of several cells in that part of the coal where the texture of the original plant could not be distinguished. The coal of the Newcastle district is considered by the Author to be of three kinds: the first, which is the greatest in quantity and the best in quality, is the rich caking coal so generally esteemed; the second is cannel or parrot coal, or splent coal of the miners; and the third, the slate coal of Jameson, which consists of the two former, arranged in thin alternate layers, and has conse

*The occurrence of living toads embedded, or rather entombed, in cavities of the deep strata has been adduced as a striking objection to the igneous theory of Hutton, and of course, as an equally striking testimony in favour of the hypothesis of aqueous solution, which commonly bears the name of Werner. Mr. Murray, the chemist, has remarked, that the lethargy of the toad and lizard may continue without the extinction of life for ages; and both these animals have been found embedded in stone: "a toad," says this author, was found under the coal seam, in the ironstone over which it rested, in a coal mine at Auchincruive, in Ayrshire." Toads have often been buried in garden pots, and found alive after long intervals. Mr. Jesse mentions an instance of a toad so buried, which at the end of twenty years was taken up much increased in bulk.

66

CELLULAR TEXTURE IN COAL.

109

quently a slaty structure. In these varieties of coal, more or less of the vegetable texture could always be discovered: thus affording the fullest evidence, if any such proof were wanting, of the vegetable origin of coal. Each of the three kinds of coal, besides the fine distinct reticulation of the original vegetable texture, exhibits other cells, filled with a light wineyellow coloured matter, apparently of a bituminous nature, and so volatile as to be entirely expelled by heat before any change is effected in the other constituents of the coal. The number and appearance of these cells vary with each variety of coal: in the finest portions, where the crystalline structure, as indicated by the rhomboidal form of its fragments, is most developed, the cells are completely obliterated: the texture being uniform and compact, and the whole arrangement indicating a more perfect union of the constituents, and a more entire destruction of the original texture of the plant. After describing these cells, and illustrating them by drawings, Mr. Hutton proceeds to speculate on their origin in the cannel coal: he considers it highly probable that they are derived from the reticular texture of the parent vegetable, rounded and confused by enormous pressure: moreover, that though the perfectly and imperfectly developed varities of coal generally occur in distinct strata, yet it is easy to find specimens which in the compass of a single square inch contain both varieties. From this fact, as also from similarity of position in the mine, the difference in the different varieties of coal are ascribed to original difference in the plants from which they were derived.*

* London and Edinburgh Phil. Mag., April, 1833.

CHAPTER VI.

THE COAL FORMATION.

Review of the arrangement of carboniferous strata, as forming coal fields, coal basins, and coal measuresArrowsmith's map of the coal districts-Somersetshire coal field-South Gloucestershire or Bristol coal field-Forest of Dean-South Welsh coal field-Shropshire field-South Staffordshire and Warwickshire North Staffordshire-North Wales -Lancashire coal field-Yorkshire, Nottinghamshire, and Derbyshire coal fields-Whitehaven coal field-Northumberland and Durham-Unexplored localities in England-Scotch coal fields-Ayrshire -Paisley-Lanarkshire-East Lothian-Culross —Irish coal fields—Districts of Leinster, Munster, Connaught, and Ulster-Description of a coal basin-Somersetshire and South Welsh basinsMantle, and inverted basin shapes-Swilleys or

small basins.

WE have already adverted to the geological position of the carboniferous group of strata (vide p. 36), where it will also be seen that the terms used at the head of the present chapter are applied to one of those five general classes or suits, into which the