PLATE XLV
THE OAR WEED (2)
This is a very fine sea-weed indeed, for it often grows to a height of ten or eleven feet. But you are not likely to see it growing, for it lives in rather deep water, where it is always covered even at the lowest tides. It is often flung up by the waves, however, and you must many times have noticed its long, thick stem and flat plate-like leaves lying upon the shore as the tide was going down.
The stem of the oar weed is often used for making the handles of knives. When it is quite fresh, it is so soft that the “tang” of a knife-blade—the part, that is, which is fastened into the handle—can be forced into it quite easily. But if it is put aside for a few months to dry it becomes as hard and solid as horn, and holds the blade so firmly that it is almost impossible to pull it out again.
If you look at the “roots” of the oar weed you will see that they are not like those of plants which grow in the ground, but are really very strong suckers. For sea-weeds do not send their roots down into the rock, as land plants do into the ground, but merely cling to the surface. That is why they are so easily torn up by the waves.
PLATE XLVI
CORALLINE (1)
For a great many years naturalists could not make up their minds whether this very pretty sea-weed was really a sea-weed or not. For it possesses the curious power of sucking out lime from the sea-water and building it up round itself, just as the polyps of the madrepores and the corals do: so that when it dies and decays it leaves a kind of chalky skeleton behind it. For this reason it was often supposed to be really a kind of coral. We know now, however, that it is a plant. For if it is placed in acid, which dissolves away this “skeleton,” we find that a true vegetable framework is left behind it.
While it is alive the coralline is of a deep purple colour. It is quite a small plant, growing only to a height of four or five inches, and you may find it in quantities on the rocks near low-water mark.
PLATE XLVI
DULSE (2)
This weed is also known as the Dillisk, or Dillosk. I dare say that you have often seen it, for it is quite common on nearly all the rocky parts of our coasts, sometimes growing on the rocks themselves, and sometimes on the larger sea-weeds. In colour, it is a deep, dark red, and if you look down upon it on a bright sunny day, as it grows in a pool of clear sea-water, you may see all kinds of lovely rainbow tints playing over its leaves. The leaves or “fronds” as they are more properly called, are about two inches long and a quarter of an inch wide.