40 FIRST FORMS OF VEGETATION. 
which cover extensive areas of mountain and lawn, 
and occupy large tracts of bogs and watery wastes, 
are barren; it being a rare thing to find on them 
capsules or any of the other compensating organs. 
They are exceedingly proliferous, throwing out 
young shoots from their sides or summits, and thus 
often increasing many feet in depth, forming layer 
above layer, the uppermost stratum alone being 
vital; the rest decomposed into peat, forming a 
rich organic soil for itsnourishment. This process 
of multiplication among the mosses is analogous to 
the process of budding in the higher plants by which, 
without sexual elements, without blossom or seed, 
a perennial plant, such as a tree, produces new in- 
dividuals from the development of its leaf-buds. 
It is extremely interesting to notice that the 
leaf is the type of the plant in the moss as in the 
flowering plant ; the veil being merely a convolute 
leaf, the lid a metamorphosed leaf, the teeth one 
or more whorls of minute flat leaves. It is by no 
means rare to find individual mosses in which 
leaves appear at the top of the fruit-stalk in place 
of the spore-case, just as happens in the phyllody 
of flowering plants, when the coloured parts of the 
flower are converted into green foliage. 
Mosses possess in a high degree the power of 
reproducing such parts of their tissue as have been 
injured or removed. They may be trodden under 
