The Fern Alliance 
which are wound round with climbing Lygodium or 
festooned with beautiful mosses. There are tall tree- 
ferns 60 feet high or more, but on the ground there are 
other smaller ones and of the most varied kinds. The 
flowering plants seem to be very much in the back- 
ground in such situations, for the shady, damp atmos- 
phere is eminently suited to ferns and mosses. 
Even in Britain one finds, here and there, deep 
valleys and ravines with the branches of tall trees 
hanging over the river, and which are enough to give 
a basis for fancies as to the coal-measure times. 
The ground may be full of male and lady ferns quite 
as beautiful as anything in the tropics. On the larger 
branches there is the inevitable moss cushion with 
rows of polypodies whose graceful fronds hang over 
into the atmosphere, which is damp and humid on 
account of the river below them, In the very shadiest 
places between the boulders one may, even to-day, dis- 
cover the filmy ferns, which are rare in Britain. 
Plenty of creepers and especially ivy and honey- 
suckle grow in such places. 
It is this sort of fern and moss glade in England, or 
the New Zealand and African tree-fern ravines, that 
inevitably recall themselves to one’s mind when looking 
through a set of coal-measure fossils. The fern-like 
appearance of most of the specimens is quite unmis- 
takable. But there must have been some very special 
characters in a forest of the Carboniferous period. 
Many of the plants exactly resembled our small club- 
mosses, but they were tall trees 60 to 80 feet in height, 
with a branching that seems stiff, clumsy, and archaic. 
The smaller fernlike plants flourished around their 
roots, but the soil was everywhere soft and slushy. In 
the Antarctic beech forests of South America one finds 
great accumulations of the sort of material from which 
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