320 Ancient Vegetation of the Earth. 



have almost a complete resemblance, in all the points of their 

 organization, with the Eqniseta (Horsetails) which grow so abun- 

 dantly 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 Calamites, then, were arborescent 

 Equiseta, a form under which these plants have wholly disap- 

 peared from the surface of the earth. 



The Lepidodendrons, of which the numerous species appear to 

 have mainly constituted the forests of this ancient epoch, and 

 which have probably contributed more than all other vegetables 

 to the formation of coal, differ very little from our Lycopodise. 

 We recognize in their trunks essentially the same structure, the 

 same mode of ramification ; and in short we see inserted upon their 

 branches leaves and fruits analogous to those, of these vegetables. 

 But, while the Lycopodi« of the present day are small plants, 

 most frequently creeping, and similar to the great mosses, attain- 

 ing very rarely one metre (about 39^ inches) in height, and cov- 

 ered with 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 sometimes attained to half a metre (over 19 J inches) 

 in length. These were, consequently, arborescent Lycopodias, 

 comparable, by their stature, to the largest Firs, of which they 

 enjoyed the rank, in this primitive world ; forming, as these now 

 do, immense forests, in the shade of which were developed 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 ! Magni- 

 tude, strength, and activity of growth, constituted its essential 

 characteristicks ; the smallest plants of our epoch were then rep- 

 resented by gigantick forms ; and yet, what simplicity of organi- 

 zation, 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 de- 

 light upon trees which are immediately distinguishable by the 

 diversity of their form, and the tints of their foliage ; and which 

 often support flowers or fruits of the most dissimilar colours. This 

 variety of aspect is still more strongly illustrated by a contem- 



