6 Reflections on Primitive Vegetation. 



that among these plants, many serve for the food of men and 

 animals, and are even indispensible to their existence. 



The variety of organization and external character display- 

 ed in the vegetables which now cover our globe, is indicated 

 by the number of natural groups into which they may be di- 

 vided. These natural groups, or families, are more than two 

 hundred and fifty in number, about two hundred belonging to 

 the class of Dicotyledonous plants, which consequently pre- 

 sent great variety of structure : and thirty to the Monocoty- 

 ledonous class. Now, the first of these classes, that is to say, 

 the two hundred families which it includes, is altogether 

 absent from the primitive flora ; and we find there scarcely 

 any traces of Monocotyledonous plants. 



The class which almost entirely constituted the vegetation 

 of the primitive world, is that of the vascular Cryptogamia, 

 which, in the present day, comprehends only five families, 

 nearly the whole of which had their representatives in the 

 ancient world ; such as the Filices, the Equiseta, and the Ly- 

 copodia. These families form what we may term the first step 

 of ligneous vegetation ; like the Dicotyledonous or Monoco- 

 tyledonous trees, they present to our view stems more or less 

 developed, of a solid texture, although of a more simple struc- 

 ture, than that of the trees before mentioned, and are decora- 

 ted with numerous leaves ; but they are destitute of those re- 

 productive organs which constitute flowers, and, instead of 

 fruit, display organs much less complicated. 



These simple and slightly diversified plants, which, from 

 their limited number and small size, occupy only an inferior 

 rank in modern vegetation, constituted, in the earliest period 

 of organic life, nearly the whole of the vegetable kingdom, 

 and formed immense forests, which have no parallel in the 

 modern creation. The rigid texture displayed in the leaves 

 of these plants, and the absence of pulpy fruits and farinace- 

 ous seeds, must have rendered them ill adapted for animal 

 food; but terrestrial animals did not then exist; the seas 

 alone possessed inhabitants ; and the vegetable kingdom then 

 held undivided sway over the visible surface of the earth, up- 

 on which it seems to have been placed, to act another part in 

 the general economy of nature. 



We cannot indeed doubt, that the immense mass of carbon 

 accumulated in the state of coal, in the bosom of the earth, 

 and arising from the destruction of vegetables which flourish- 

 ed at this distant period, on the surface of the globe, must 

 have been imbibed by them from the carbonic acid present 

 in the atmosphere ; the only form under which carbon, not 

 arising from the destruction of pre-existing organic bodies, 



