A PIECE OF COAL. 
1/9 
Fig. 50. 
learn exactly how they were built up inside, and com- 
pare them with the stems of living plants, while the 
fruits cc and the little round spores lying near them, 
tell him their history as well as if he had gathered them 
from the tree. In this way we have learnt to know 
very fairly what the plants of the coal were like, and 
you will be surprised when I tell you that the huge 
trees of the coal-forests, of which we sometimes find 
trunks in the coal-mines from ten to fifty feet long, are 
only represented on the 
earth now by small insig- 
nificant plants, scarcely 
ever more than two feet, 
and often not many 
inches high. 
Have you ever seen 
the little club-moss or Ly- 
copodium which grows 
all over England, but 
chiefly in the north, on 
heaths and mountains ? 
At the end of each of 
its branches it bears a 
cone made of scaly 
leaves ; and fixed to the 
inside of each of these 
leaves is a case called 
a sporangium, full of little spores or moss-seeds, as 
we may call them, though they are not exactly like true 
seeds. In one of these club-mosses called Selaginella, 
the cases B near the bottom of the cone contain large 
spores b, while those near the top, A, contain a 
N 2 
Selaginella sclaginoides. 
Species of club-moss bearing two 
kinds of spores. 
