12 REMARKS ON THE VEGETATION OF THE 
will be detected in this first period of vegetation than was formerly sus- 
pected. 
The more, therefore, that geologists will interest themselves in promot- 
ing the examination of these ancient relics, the more likely are they to ac- 
celerate the approach of a period when we shall be able, with greater cer- 
tainty, to ascertain each deposit by the peculiarity of its vegetable fossils. 
The essential character of this first period of vegetation, is thus proved 
to be the predominance of vascular cryptogamic plants; and we have here a 
most striking example of the great development which the species in ques- 
tion attained at this early period of vegetable creation, when the two great 
agents, heat and moisture, had evidently exerted an extraordinary influence. 
Geologists have entertained, and_ still entertain, very different notions 
respecting the origin of Coal. It appears very probable, from the singular 
development of the vegetation of the first period, that these different com- 
bustible beds may have been deposited as a kind of peat, of greater or less 
extent, formed from the remains of vegetables, and on which other vege- 
tables still grew. This opinion is, I think, greatly confirmed by the de- 
scription just given of the Newcastle coal-field. It appears also the more 
probable, as it is well known that many plants of the families composing 
this early vegetation grow abundantly in places of this kind at the present 
day. The Equiseta, the Lycopodia, the Osmunda regalis, the Pteris aqui- 
lina, various Aspidia, and other ferns, are indigenous to our peat soils. 
Again, we can scarcely doubt, that, at this remote epoch, our atmosphere 
had a very different composition from what it now has, and that it exerted 
amore powerful influence upon the development of these constituents of 
our combustible beds. 
The comparison of the successive development of vegetables and ani- 
mals, is not one of the least remarkable parts of the study of these fossil or- 
ganized bodies. This is beautifully expressed by M. ADOLPHE Brone- 
NIART. He displays, by philosophic reasoning, the effects produced by a 
supposed cause. He states, with great perspicuity, why land animals did 
not exist at one period—why cold-blooded animals became more numerous 
at another period; and, lastly, gives cogent reasons for the appearance of 
