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Tertiary series. Many additional species have been collected from each of these series, but are not yet named.

As the known species of living vegetables are more than fifty thousand, and the study of fossil botony is as yet but in its infancy, it is probable that a large amount of fossil species lies hid in the bowels of the earth, which the discoveries of each passing year will be continually bringing to light.

The plants of the First period are in a great measure composed of Ferns, and gigantic Equisetacea; and of families, of intermediate character between existing forms of Lycopodiacea and Coniferæ, e. g. Lepidodendriæ, Sagillariæ, and Stigmariæ; with a few Coniferæ.

Of plants of the Second period, about one-third are Ferns: and the greatest part of the remainder are, Cycadeæ and Coniferæ, with a few Liliaceae. More species of Cycades occur among the fossils of this period, than are found living on the present surface of the earth. They form more than one-third of the total known fossil Flora of the Secondary formations; whilst of our actual vegetation, Cycadeæ are not one-thousandth part.

The vegetation of the Third period approximated closely to that of the existing surface of the globe.

Among living families of plants, Sea-weeds, Ferns, Lycopodiaceæ, Equisetaceae, Cycadeæ and Coniferæ, bear the nearest relation to the earliest forms of vegetation that have existed upon our planet.

The family which has most universally pervaded every stage of vegetation is that of Coniferæ ; increasing in the number and variety of its genera and species, at each successive change in the climate and condition of the surface of the earth. This family forms about one three-hundreth part of the total number of existing vegetables.

Another family which has pervaded all the Series of formations, though in small proportions, is that of Palms.

The view we have taken, of the connexions between the extinct and living specimens of the vegetable kingdom, sup

plies an extensive fund of arguments, and lays open a new and large field of inquiry, both to the Physiologist, and to the student in Physico-Theology.

In the fossil Flora, we have not only the existing fundamental distinctions between Endogenous and Exogenous plants, but we have also agreement in the details of structure throughout numerous families, which indicates the influence of the same Laws, that regulate the development of the living members of the vegetable kingdom.

The remains of Fructification, also; found occasionally with the plants of all formations, show still farther, that the principles of vegetable Reproduction have at all times been the same.

The exquisite organizations which are disclosed by the microscope, in that which to the naked eye is but a log of Lignite, or a lump of Coal, not only demonstrate the adaptation of means to ends, but the application also of similar means, to effect corresponding ends, throughout the several Creations which have modified the changing forms of vegetable life.

Such combinations of contrivances, varying with the varied conditions of the earth, not only prove the existence of a Designer from the existence of method, and design; but from the Connexion of parts, and Unity of purpose, which pervade the entirety of one vast, and complex, but harmonious Whole, show that One, and the same Mind gave origin and efficacy to them all.

CHAPTER XIX.

Proofs of Design in the Dispositions of Strata of the Carboniferous Order.

IN reviewing the History and geological position of vegetables which have passed into the state of mineral coal, we have seen that our grand supplies of fossil fuel are derived

almost exclusively from strata of the Transition series. Examples of Coal in any of the Secondary strata are few and insignificant; whilst the Lignites of the Tertiary formations, although they occasionally present small deposites of compact and useful fuel, exert no important influence on the economical condition of mankind.*

It remains to consider some of the physical operations on the surface of the Globe, to which we owe the disposition of these precious Relics of a former world, in a state that affords us access to inestimable treasures of mineral Coal.

We have examined the nature of the ancient vegetables from which Coal derives its origin, and some of the processes through which they passed in their progress towards their mineral state. Let us now review some farther important geological phenomena of the carboniferous strata, and see how far the utility arising from the actual condition of this portion of the crust of the globe, may afford probable evidence that it is the result of Foresight and Design.

It was not enough that these vegetable remains should have been transported from their native forests, and buried at the bottom of ancient lakes and estuaries, and seas, and there converted into coal; it was farther necessary that great and extensive changes of level should elevate, and convert into dry and habitable land, strata loaded with riches, that would for ever have remained useless, had they continued entirely submerged beneath the inaccessible

* Before we had acquired by experiment some extensive knowledge of the contents of each series of formations which the Geologist can readily identify, there was no à priori reason to expect the presence of coal in any one Series of strata rather than another. Indiscriminate experiments in search of coal, in strata of every formation, were therefore desirable and proper, in an age when even the name of Geology was unknown; but the continuance of such Experiments in districts which are now ascertained to be composed of non-carboniferous strata of the Secondary and Tertiary Series, can no longer be justified, since the accumulated experience of many years has proved, that it is only in those strata of the Transition Series which have been designated as the Carboniferous Order, that productive Coal-mines on a large scale have ever been discovered.

depths, wherein they were formed; and it required the e ercise of some of the most powerful machinery in the Dyn mics of the terrestrial globe, to effect the changes that we requisite to render these Elements of Art and Industry a cessible to the labour and ingenuity of man. Let us brief examine the results that have been accomplished.

The place of the great Coal formation, in relation to t other series of strata, is shown in our first section (Pl. Fig. 14.) This ideal section represents an Example of di positions which are repeated over various areas upon t crust of the Globe.*

The surface of the Earth is found to be covered with series of irregular depressions or Basins, divided from o another, and sometimes wholly surrounded by projecti portions of subjacent strata, or by unstratified crystalli rocks, which have been raised into hills and mountains, various degrees of height, direction and continuity. either side of these more elevated regions, the strata d with more or less inclination, towards the lower spaces b tween one mountain range and another. (See Pl. 1.)

This disposition in the form of Troughs or Basins, whi is common to all formations, has been more particular demonstrated in the Carboniferous Series, (See Pl. 65. Fi 1, 2, 3.) because the valuable nature of beds of Coal oft causes them to be wrought throughout their whole extent.

One highly beneficial result of the basin-shaped dispositi of the Carboniferous strata has been, to bring them all the surface around the circumference of each Basin, and render them accessible, by sinking mines in almost eve part of their respective areas; (See Pl. 65. Figs. 1, 2, 3 An uninterrupted inclination in one direction only, wou have soon plunged the lower strata to a depth inaccessib

to man.

• The Coal Formation is here represented as having partaken of the sa elevatory movements, which have raised the strata of all formations towa the mountain Ridges, that separate one basin from another basin.

The Basin of London, (Pl. 68.) affords an example of a similar disposition of the Tertiary strata reposing on the Chalk. The Basins of Paris, Vienna, and of Bohemia, afford other examples of the same kind. (See Pl. 1. Figs. 24-28.)

The Secondary and Transition strata of the central and North Western districts of England, are marginal portions of the great geological Basin of Northern Europe; and their continuations are found in the plains, and on the flanks of mountain regions on the Continent.*

These general dispositions of all strata in the form of Troughs or Basins have resulted from two distinct systems of operations, in the economy of the terraqueous globe; the first producing sedimentary deposites, (derived from the ma

* The section (Pl. 66. Fig. 1.) shows the manner in which the Strata of the Transition Series are continued downwards between the Coal formation and the older members of the Grauwacke formation through a series of deposites, to which, Mr. Murchison has recently assigned the name of the "Silurian system." This Silurian System is represented by No. 11, in our Section, Fig. 1. The recent labours of Mr. Murchison in the border counties of England and Wales have ably filled up what has hitherto been a blank page, in the history of this portion of the vast and important Systems of rocks, included under the Transition series; and have shown us the links which connect the Carboniferous system with the older Slaty rocks. The large group of deposites to which he has given the appropriate name of Silurian system, (as they occupy much of the Territory of the ancient Silures,) admits of a four-fold division, which is expressed in the section Pl. 66. Fig. 1. This section represents the exact order of succession of these Strata in a district, which must henceforth be classic in the Annals of Geology.

In September, 1835, I found the three uppermost divisions of this system, largely developed in the same relative order of succession on the south frontier of the Ardennes, between the great Coal formation and the Grauwacke. See Proceedings of the Meeting of the Geological Society of France at Mézières and Namur, Sep. 1835, Bulletin de la Société Géologique de France, Tom VII.) The same subdivisions of the Silurian system, maintain their relative place and importance over a large extent of the mountainous district of the Eifel, between the Ardennes and the Valley of the Rhine; and are continued East of the Rhine through great part of the duchy of Nassau. (Stiffts Gebirgs-Karte, von dem Herzogthum-Nassau. Wiesbaden,

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