8 Reflections on Primitive Vegetation. 



triple that which is presented by the largest species of the 

 temperate climates. Another circumstance appears to have 

 a still more decided influence on their preponderance, in re- 

 lation to plants belonging to other families, namely, humidity 

 and uniformity of climate ; conditions which are found in the 

 greatest degree of perfection in small islands, at a distance 

 from continents. 



In these isles, indeed, the extent of the surrounding seas 

 causes a constant humidity, and a temperature but little ex- 

 posed to change, which seem, in a remarkable degree, to fa- 

 vour the developement and increase of species among the ferns 

 and other similar vegetables ; while phanerogamous plants, on 

 the contrary, are, under the same influence, much fewer in 

 number, and in small variety. The result follows, that while 

 in the great continents, the vascular plants of the class Cryp- 

 togamia, such as the Filices, Equiseta and Lycopodia, often 

 form scarcely a fiftieth part of the whole number of vegetables, 

 in the small islands of the equinoctial regions, these plants 

 constitute almost half, and sometimes even two thirds, of the 

 whole number of the vegetable tribes which inhabit them. 



The Archipelagoes situated between the tropics, such as the 

 Antilles, or the islands of the great Pacific ocean, are then the 

 parts of the globe which display, in the present day, a ve- 

 getation most nearly corresponding to that which existed on 

 the earth, when the vegetable kingdom began, for the first 

 time, to be developed. 



We are consequently led, by the study of the vegetables 

 which accompany the beds of coal, to infer that at this early 

 period the surface of the earth, in the countries producing the 

 best known of these coal-deposits, namely, Europe and North 

 America, possessed a state of climate similar to that now ex- 

 isting in the Archipelagoes of the equinoctial regions, and, 

 probably, a geographical configuration very little different. 



When we consider the number and thickness of the beds 

 which constitute the greater part of the coal strata, and when 

 we examine, from first to last, the changes which have opera- 

 ted on the specific form of the vegetables to which they owe 

 their origin, we are constrained to acknowledge that this lux- 

 uriant vegetation of the primitive world, must have covered, 

 with its dense forests, all those portions of the globe which 

 were raised above the level of the sea ; for it presents itself, 

 with the same characters, in Europe, and in America; equato- 

 rial Asia, as well as New Holland, seem also to have partaken 

 of this general uniformity of vegetable structure. 



Nevertheless, this first vegetable creation was shortly to 

 disappear, that it might give place to another, composed of 



