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Every known living species.* These leaves are too well preserved to have endured transport by water from a distant region, and must apparently be referred to extinct species, which in the Tertiary period, were indigenous in Europe.
No pinnated Palm leaf has yet been found in the Tertiary Strata, although the number of these forms among existing palms, is more than double that of the flabelliform leaves.f
Fossil Fruits of Palms.
Many fossil fruits of the Tertiary period belong to the family of Palms, all of which, according to M. Ad. Brongniart, seem derived from Genera that have pinnated leaves. Several such fruits occur in the Tertiary clay of the Island of Sheppey; among which are the Date,J now peculiar to Africa and India; the Cocoa-nut,§ which grows universally within the tropics; the Bactris, which is limited to America; and the Areca, which is found only in Asia. Not one of these can be referred to any flabelliform palm. Fossil Cocoa-nuts occur also at Brussels, and at Liblar near Cologne, together with fruits of the Areca.
* The leaf represented in PI. 64. fig. 1. is that of a flabelliform Palm (Palmacites Lamanonis,) from the Gypsum of Aix in Provence; similar leaves have been found in three other parts of France, near Amiens, Mans, and Angers, all in strata of the Tertiary epoch. Another species (Palmacites Parisiensis) has been found in the Calcaire Grossicr, near Versailles (Cuvier and Brongniart, Geognosie des Environs de Paris, PI. 8, fig. 1. E.) A third species of Palm leaf (Palmacites flabellatus) occurs in the Molasse of Switzerland, near Lausanne, and in the Lignite of Hoering, in TyrolSee PI. 1, figs. 13. 66.
t The Date, Cocoa-nut Palm, and Areca are familiar examples of Palms having pinnated leaves. See PI. 1. figs. 67. 68.
t See Parkinson's Org. Rem. Vol. i. PI. VI. fig. 4, 9.
§ See Parkinson's Org. Rem. Vol. i. PI. VII. fig. 1—5. M. Brongniart says, these fruits are undoubtedly of the Genus Cocos, near to Cocoa lapidea, of Gasrtner.
Although all these fruits belong to Genera whose leaves are pinnated, no fossil pinnated Palm leaves (as we have just stated,) have yet been found in Europe. It seems therefore most likely, from the mode in which so large a number of miscellaneous fruits are crowded together in the Isle of Sheppey, mixed with marine shells and fragments of timber, almost always perforated by Teredines, that the fruits in question were drifted by marine currents from a warmer climate than that which Europe presented after the commencement of the Tertiary Epoch; in the same manner as tropical seeds and logs of mahogany are now drifted from the Gulf of Mexico to the Coasts of Norway and Ireland.
Besides the fruits of Palms, the Isle of Sheppey presents an assemblage of many hundred species of other fruits,* most of them apparently tropical; these could scarcely have been accumulated, as they are, without a single leaf of the tree on which they grew, and have been associated with drifted timber bored by Teredines, by any other means than a sea-current.
We have no decisive information as to the number of species of these fossil fruits; they have been estimated at from six to seven hundred.f In the same clay with them are found great numbers of fossil Crustaceans, and also the remains of many fishes, and of Crocodiles, and aquatic Tortoises.
• According to M. Ad. Brongniart, many of these have near relation to the aromatic fruits of the Amomum (cardomom,) they are triangular, much compressed, and umbilicated at the summit, which presents a small circular areola, apparently the cicatrix of an adherent calyx; within are three valves. A slight furrow passes along the middle of each plain surface, similar to that on the fruit of many acitamineous plants. These Sheppey fruits, however, cannot be identified with any known Genus of that Family, but approach so nearly to it, that Ad. Brongniart gives them the name of Amomocarpum.
-f See Parkinson's Organic Remains, Vol. i. PI. 6, 7. Jacob's Flora Favershamensis. And Dr. Parsons, in Phil. Trans. Lond. 1757, Vol. 50, page 396, PI. XV. XVL A collection of these fruits is preserved in the British "Museum, another in the Museum at Canterbury, and a third in that of Mr. Bowerbank, in London.
As the drifted seeds that occur in Sheppey seem to have been collected by the action of marine currents, the history of European vegetation during the Tertiary period, must be sought for in those other remains of plants, whose state and circumstances show that they have grown at no great distance from the spot in which they are now found.*
The following is a summary of what is yet known, respecting the varying conditions of the Flora of the three great periods of Geological history we have been considering.
The most characteristic distinctions between the vegetable remains of these periods arc as follows. In the first period, the predominance of vascular Cryptogamic, and comparative rarity of Dicotyledonous plants. In the second, the approximation to equality of vascular Cryptogamic, and Dicotyledonous plants.f In the third, the predominance of Dicotyledonous, and rarity of vascular Cryptogamic plants. Among existing vegetables almost two-thirds are Dicotyledonous.
The Remains of Monocotyledonous plants occur, though sparingly, in each period of Geological formations.
The number of fossil plants a» yet described is about five hundred; nearly three hundred of these are from strata of the Transition series; and almost entirely from the Coal formation. About one hundred are from strata of the Secondary series, and more than a hundred from formations of the Tertiary series. Many additional species have been collected from each of these series, but are not yet named.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.
* The beautiful Amber, which is found on tlie eastern shores of England, and on the Coasts of Prussia and Sicily, and which is supposed to be fossil resin, is derived from beds of Lignite in Tertiary strata. Fragments of fossil gum were found near London in digging the tunnel through the London clay at Highgate.
j- The dicotyledonous plants of the Transition and Secondary formations present only that peculiar tribe of this class, which is made up of Cycadeae; and Coniferae, viz. Gymnospermous Phanerogamic.
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 Equisetaceae; and of families, of intermediate character between existing forms of Lycopodiaceae and Coniferae, e. g. Lepidodendriae, Sagillariae, and Stigmarise; with a few Coniferae.
Of plants of the Second period, about one-third are Ferns: and the greatest part of the remainder are, Cycadeae and Coniferae, with a few Liliaceae. More species of Cycadeae 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, Cycadeae 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, Lycopodiaceae, Equisetaceae, Cycadeae and Coniferae, 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 Coniferae; 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~
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.
Proofs of Design in the Dispositions of Strata of the Carbo~ niferous 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