Ancient Vegetatioji of the Earth. 321 



plation of the diversified shrubs and plants which fringe the bor- 

 ders 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 diversity of structure, among these plants, 

 many varieties suited to the nourishment of man or of animals ; 

 and indeed such as are even indispensable 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 wTiich they are capable of being divided. 

 These groups or natural families amount to more than two hun- 

 dred and fifty, of which about two hundred belong to the class 

 of the Dicotyledons, (which consequently present the greatest 

 variety of structure,) and thirty to that of the Monocotyledons. 

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

 which they contain, are completely wanting in our primitive 

 flora, and seldom can we there recognize 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 comprehends no more than five families ; almost all of 

 which had parallels in the ancient world ; such are the Ferns, 

 Equiseta and Lycopodias. These families constitute, thus to 

 speak, the first degree of ligneous vegetation : they present, like 

 the arborescent Dicotyledons or Monocotyledons, trunks more or 

 less developed, of a solid texture, although more simple than 

 those of these trees, and garnished with numerous leaves ; but 

 they are deprived of those reproducing organs which constitute 

 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 dimensions, rise not above a 

 very inferiour rank, in our present vegetation, constituted, in the 

 dawn of the creation of organized beings, almost the entire vege- 

 table kingdom, and formed forests so immense that we find not 

 their analogy in modern times. The rigidity of the leaves of 

 these vegetables, 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 



Vol. XXXIY.— No. 2. 41 



