The Fern Alliance 
our coal may have been formed, It is not peat, nor 
liquid mud, nor leaf-mould, but a slush more or less 
resembling them. 
Great thickets of reeds very like our common horse- 
tails (Equisetum limosum), but also 60 to 80 feet high, 
would flourish along the banks of the sluggish rivers or 
fringe the great coal-measure lagoons. 
The rootlets of these extinct Calamariz can some- 
times be traced in a distinct and definite layer closely 
resembling Equisetum deposits in a lowland bog. 
Beside the pools of black water were marsilea-like, 
fern-like, and other herbaceous plants. 
Gigantic, bony-plated, salamander-like animals from 
6 to 8 feet long wallowed in those slimy waters, where 
also were plenty of the fishes on which they fed. 
The atmosphere in these forests and marshes would 
be damp and still. 
There was no lack of animal life, for things like ear- 
wigs lived upon the branches, and upon the ground 
were great millipedes, very like the huge forms which 
are common in the Madagascar jungle, and which roll 
up into a ball an inch or more in diameter when dis- 
turbed. We should also mention gigantic insects, such 
as the great maybugs, which were probably devoured 
by large dragon-flies, two feet across the wing, and 
very likely brilliantly coloured. 
The really important part of those forests was the 
black slush or slime of the forest pools and slow rivers, 
for in them the bodies of the animals and of algz, as 
well as other vegetable matter, turned to bituminous coal. 
There is a graphic description by Stokes and Watson ” 
of the conditions in those days of certain flat, swampy 
levels between the higher ground and the sea. Here 
were groves of large trees which grew in brackish water, 
or in mud like that of a mangrove swamp. 
81 F 
