We must not forget the grass of the sea.  It grows in narrow blades, often a yard in length, and as wide as your thumb.  It is not a sea-weed, but a real flowering plant, which, for some reason or other, loves to grow under water.  It creeps in the sand and mud, with green leaves growing up as thick as corn in a cornfield.

All these waving green leaves make large meadows in the sea; and sea-snails, fishes, and crabs hide in it, just as all manner of living things hide in the grass of our meadows.  The proper name of this strange plant is Sea Wrack.  When dried, it is useful for packing up china, and covering flasks of oil.

Now we come to the real use of sea plants.  They are food for all the hosts of small animals of the sea.  These eat it as it grows; or else, like the mussel and oyster, swallow the tiny scraps of it which float everywhere like so much dust.

The shell-fish, and other animals which feed on sea plants, are themselves eaten by other sea creatures, and these in their turn are eaten by crabs, lobsters and fish, which are eaten by us.  It reminds you of a chain.  The first link in the chain is the sea plant, the last links are the fish and ourselves.  So, you see, the weeds and grass of the ocean are of very great value indeed.

EXERCISES

1.  Give the names of three common Sea-weeds.

2.  What is the colour of the weed found in deep water?

3.  Why cannot Sea-weed grow in very deep water?

4.  In what way are sea plants most useful?

LESSON IX.

THE JELLY-FISH.

Or all the queer children of Nature which live in the sea, the Jelly-fish is one of the queerest.  You often find it on the shore, especially after a severe storm.  There it lies, a mass of helpless jelly, which slips and breaks through your fingers if you try to lift it.

It cannot move back to its watery home, and in a short time the sun’s warmth will have dried it up, leaving but a mark on the sand, and a few scraps of animal matter; for these strange creatures are little else but water.  A Jelly-fish, which weighed two pounds when alive, would leave less than the tenth part of one ounce when dried!

There is a story of a farmer who, on seeing thousands and thousands of Jelly-fish along the shore, thought he would make use of them.  He decided that they would serve as manure for his fields, and so save him much money.  He went home, and sent men with wagons to be loaded with the Jelly-fish.  This was done, and the Jelly-fish were spread over the soil.  On looking at his fields the next morning, the farmer was astonished to find that every scrap of his new manure had vanished as if by magic!

[Illustration:  WEST PAN SAND BUOY.  ONE OF THE MANY BUOYS AT THE MOUTH OF THE THAMES.]

In the sea the Jelly-fish looks like an umbrella of bluish-white jelly, from which hang tassels and threads.  Look over the side of a boat, or from the pier, and you often see them drifting by, hundreds of them, like so many ghosts.