This, then, is the curious history of lichens; the green cells and fungi flourishing together in the damp winter and bearing the hardest frost far better than the summer drought, so that they have their good time when most other plants are dead or asleep. Yet though some of them, such as the hairy lichens, almost disappear in the summer, they are by no means dead, for, like all these very low plants, they can bear being dried up for a long time, and then, when moisture visits them again, each green cell sets to work, and they revive. There is much more to be learnt about them, but this will be sufficient to make you feel an interest in their simple lives, and when you look for them in the wood you will be surprised to find how many different kinds there are, for it is most wonderful that such lowly plants should build up such an immense variety of curious and grotesque forms.
And yet, when we turn to the mosses, I am half afraid they will soon attract you away from the dull grey lichens, for of all plant histories it appears to me that the history of the moss-plant is most fascinating.
As this history is complicated by the moss having, as it were, two lives, you must give me your whole attention, and I will explain it first from diagrams, though you can see all the steps under the microscope.
Fig. 32.
A stem of feathery moss. (From life.)
l, Leaves. s, Stem.
r, Roots.
Take in your hands, in the first place, a piece of this green moss which I have brought. How thick it is, like a rich felted carpet! and yet, if you pull it apart carefully, you will find that each leafy stem is separate, and can be taken away from the others without breaking anything. In this dense moss each stem is single and clothed with leaves wrapped closely round it (see Fig. 33); in some mosses the stem is branched, and in others the leaves grow on side stalks, as in this feathery moss (Fig. 32). But in each case every stem is like a separate plant, with its own tuft of tender roots r.
What a delicate growth it is! The stem is scarcely more than a fine thread, the leaves minute, transparent, and tender. In this pale sphagnum or bog-moss (Fig. 36, p. 93), which is much larger and stouter, you can see better how each one of these leaves, though they are so thickly packed, is placed so that it can get the utmost light, air, and moisture. Yet so closely are the leaves of each stem entangled in those of the next that the whole forms a thick springy green carpet under our feet.