176 AMONG THE WILD FLOWERS. 
duced in vast quantities, and ignite like gun- 
powder, but without smoke. ‘The spikes are 
usually in pairs. The varieties of Lycopodium, 
and another similar plant, Selaginella, in the 
greenhouse, need only be mentioned to recall 
their value in the way of ornament. 
The Mosses, W/uscz, are a distinct and wide 
study, beyond the scope of these papers ; as are 
also the Lzverworts, which clothe the dark and 
damp recesses with their peculiar green, and 
the Lzchens which will cover the driest bark or 
tiled roof. The innumerable /unxgz and Alge 
are equally beyond our scope, though full of 
beauty and interest. The very curious plants 
of the genus Chara grow wholly submerged ; 
they have numerous brittle, pale stems, without 
any leaves. The fructification, in the axils of 
the outer tube-like stem, consist of globules of 
two kinds, of a brick-red colour, containing 
granular matter and spiral filaments. Some of 
the plants display the circulation of the sap, 
under the microscope. 
It is impossible to do more than name these 
several numerous and interesting families. 
