THE FERN FORESTS OF 
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which makes the central part of the picture ; 
large herds of the Palaeotherium, tlie ancient 
Pachyderm, reconstructed with such accuracy by 
Cuvier, are feeding along its banks ; and a tall 
bird of the Heron or Pelican kind stands watch- 
ing by the water’s edge. In the Miocene the 
vegetation looks still more familiar, though the 
Elephants, roaming about in regions of the Tem- 
perate Zone, and the huge Salamanders, crawling 
out of the water, remind us that we are still far 
removed from present times. Lastly, we have 
the ice period, with the glaciers coming down to 
the borders of a river where large troops of Buf- 
falo are drinking, while on the shore some Lears 
are feasting on the remains of a huge carcass. 
It is, however, with the Carboniferous age that 
we have to do at present, and I will not antici- 
pate the coming chapters of my story by dwelling 
now on the aspect of the later periods. To re- 
turn, then, to the period of the coal, it would 
seem that extensive freshets frequently over- 
flowed the marshes, and that even after many 
successive forests had sprung up and decayed 
upon their soil, they were still subject to submer- 
gence by heavy floods. These freshets, at certain 
intervals, are not difficult to understand, when 
we remember, that, beside the occasional influx 
of violent rains, the earth was constantly under- 
going changes of level, and that a subsidence or 
