1S3S] 



FARMERS' REGISTER 



827 



attentive comparison ot' (Iiose products of tlie 

 equinoctial regions with tiiose trunks, the growth 

 of tlie ancient world, sniiiccs to dis^^ipate ail rela- 

 tions!, which are founded only on pome resem- 

 blances in the general aspect, that have been at- 

 tempted to be established between them ; and a 

 more prolbund examination, either of these trunks 

 or of the leaves which accompany them, readily 

 shows that the vejielables which formed these 

 primitive forests are not identical with any trees 

 still found flourishmg upon the earth. 



The arborescent ferns which, by the elegance 

 and magnitude of their exterior, now form one of 

 the principal ornaments of the equatorial regions, 

 are the onlj' arb'orescent vegetables which are re- 

 cognized, even in small number, among the trees 

 of this antique vegetation. 



As to the other fossil stems, remains of these 

 primitive forests of the ancient world, it is among 

 the most humble vegetables of our epoch that we 

 must seek their analogues. 



For instance, the calamites, which attained 

 from four to five metres (a little more than 13 to 

 16 feet) of height, and from one to two decimetres 

 (not quite (bur to eight inches) of diameter, have 

 almost a complete resemblance, in all the points 

 of their organization, with the equiseta (horse- 

 tails) which grow so abundantly in the marshy 

 situations of our climates, and of which the stems, 

 hardly as large as the finger, rarely surpass one 

 metre (about 39^ inches) in height. The cata- 

 mites, then, were arborescent equiseta, a form 

 under which these plantn have wholly disappeared 

 from the surface of the earth. 

 ^ The lepidodendrons, of which the numerous 

 species appear to have mainly constituted the fo- 

 rests of this ancient epoch, and which have pro- 

 bably contributed more than all other vegetables 

 to the formation of coal, differ very little from our 

 lycopodia^. We recognize in their trunks essen- 

 tially the same structure, the same mode of rami- 

 fication ; and in short we see inserted upon their 

 branches leaves and fruits analogous to those of 

 these vegetables. But, while the lycopodia? of 

 the present day are small plants, most frequently 

 creeping, and similar to the great mosses, attain- 

 ing very rarely one metre (about 39J inches) in 

 height, and covered wi:h very diminutive leaves, 

 the lepidodendrons, preserving the same form 

 and aspect, elevated themselves to twenty or 

 twenty-five metres (a little more than 65 to 82 

 feet,) having, at their base, near one metre (about 

 39^ inches) of diameter, with leaves which some- 

 times attained to half a metre (over 19^ inches) 

 in length. These were, consequently, arbores- 

 cent lycopodia;, comparable, by their stature, to 

 the largest firs, of which they enjoyed the rank, 

 m this primitive world ; forming, as these now do, 

 immense forests, in the shade of which were de- 

 veloped the ferns, so numerous at that period. 



How different this powerful vegetation from 

 that which now clothes, in ever-varying tints, the 

 surface of the earth! Magnitude, 'strength, and 

 activity of growth, constituted its essential cha- 

 racteristicks ; the smallest plants of our epoch 

 were then represented by gigantick forms ; and 

 yet, what simplicity of organization, and what 

 uniformity in the midst of a vegetation so enor- 

 mous! 



At the present day, even in those regions 

 where nature has suffered no change at the hand 



of man, the eye reposes with delight upon trees 

 which are immediately dislinguishuble by the di- 

 versity of their form, and the tints of their foliage; 

 and which often support flowers or Ir-uils of the 

 most dissimilar colors. This variety of aspect ia 

 still more strongly illustrated by a contemplation 

 of the diversified shrubs and plants which fringe 

 the borders of our forests, or adorn our meadows, 

 and of which the flowers exhibit to us almost all 

 the tints of the prism. Finally, there result from 

 this divei^ity of structure, among these plants, 

 many varieties suited to the nourishment of man 

 or of animals; and indeed such as are even indis- 

 pensable to their existence. 



The variety in the organization and aspect of 

 the vegetables which at present cover our globe 

 is indicated by the number of natural groups into 

 which they are capable of being divided. These 

 groups or natural fannlies amount to more than 

 two hundred and fifty, of which about two hundred 

 belong to the class of the dicotyledons, (which 

 consequently present the greatest variety of struc- 

 ture,) and thirty to that of the monocotyledons. 

 Now the first of these classes, that is, the two 

 hundred families which they contain, are com- 

 pletely wanting in our primitive flora, and seldom 

 can we there recognise any indications of the 

 monocotyledons. 



The class which constituted, almost alone, the 

 vegetation of this primitive world is that of the 

 vascular cryptogamia, which at present compre- 

 hends no more than five families; almost all of 

 which had parallels in the ancient world ; such are 

 the ferns, equiseta and lycopodia?. These fa- 

 milies constitute, thus to speak, the first degree of 

 ligneous vegetation : they present, like the arbor- 

 escent dicotyledons or monocotyledons, trunks 

 more or less developed, of a solid texture, although 

 more simple than those of these trees, and gar- 

 nished with numerous leaves ; but they are de- 

 prived of those reproducing organs which consti- 

 tute the flowers, and they present, in place of fruit, 

 organs much less complicated. 



These plants, so simple, so little varied in their 

 organization, and which, by their number and di- 

 mensions, rise not above a very inferior rank, in 

 our present vegetation, constituted, in the dawn of 

 the creation of organized beings, almost the en- 

 tire vegetable kingdom, and formed forests so im- 

 mense that we find not their analogy in modern 

 times. The rigidity of the leaves of these vege- 

 tables, the absence of fleshy fruits and farinaceous 

 seeds, would have rendered them very unfit to 

 have served as aliment to animals: but terrestrial 

 animals, at the time of their growth, had not yet 

 existence; the seas alone offered numerous inha- 

 bitants ; and the vegetable kingdom, at that pe- 

 riod, maintained undivided sway over all the un- 

 deluged portions of the earth ; upon which it 

 seems to have been called to play another part, in 

 the economy of nature. 



We cannot doubt, in truth, that the immense 

 mass of carbon accumulated in the bosom of the 

 earth, in a state of coal, and which is the product 

 of the destruction of those vegetables which grew 

 at that ancient epoch, upon the surface of the 

 globe, has been imbibed, by those vegetables, in 

 the carbonic acid of the atmosphere — the only 

 form under which carbon, not derived from the 

 destruction of preexisting, organized heings, can 

 be absorbed by plants. 



