R. Cadwallader Smith

“ 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. ”

“ We explored such a beach as that in our last lesson. There are long, long stretches of sand and thin grass in other places, or else mile after mile of muddy, dreary, salt marshes.
Birds are to be found on every kind of coast. Some, like the Seagull, wander far and wide. Others keep to the cliffs, and many find all they need in the wide mud-flats. Such an army is there of these shore birds, that we cannot even glance at them all in this lesson. So we will take a few of them only--the Black-headed Gull, the Cormorant, the Ringed Plover, the Oyster-catcher and the Redshank. ”

“ The dry, shifting sand, and the salt spray, are enough to kill them, you would think. They have no shelter from the strong sea wind, nor from the fierce glare of the summer sun. The puzzle is, how do they live among so many enemies? For you know that the flowers of the field would at once die if you planted them in salt and sand. They would starve to death.
Even the strongest seaside plants shun that part of the beach washed by the waves. ”

“ It lives in sand, and can bury itself so quickly that you would have to use your spade with all your might in order to keep pace with this little shell-fish. Where Cockles have buried themselves you will see spurts of water and sand, showing where they are busy down below in the wet sand.
Besides being so skilful at digging, the Cockle is a first-rate jumper. If left on the beach, it jumps over the sand, towards the sea, in the funniest way. It is strange to see a quiet-looking shell suddenly take to hopping and jumping like an acrobat. ”

“ Now these rocks are the bare bed of the shore, stripped of all covering. There is no mud, sand, or shingle, so here you see plainly the work done by the restless water. On every side you notice rocks worn to all shapes and sizes. Some jut out as sharp ledges. Others are flat tables, covered with a table-cloth of sea-plants. These clothe the rocks, or hang over the ledges like wet, shining green curtains. Nearly every rock has its crust of barnacles and clumps of mussels. If we are not careful we slip on the wet weeds, and get a ducking in the pools which lie everywhere among the rocks. ”

“ The feathers are so coloured and the colours are so arranged that, once among the grey, yellow, black, and white pebbles on the beach, the little bird is invisible. It is as if the earth had swallowed him up.
The eggs, too, are just as hard to find. There is no nest to "give the game away"; and the eggs look just like the pebbles amongst which they are laid. The young ones are protected from their enemies in the same way, and they crouch, as still as death, amid the stones which they so much resemble. ”

“ When covered with sea-water the ugly blobs of jelly open out like beautiful flowers. In some places along our coast the floor of the sea is like a flower garden, gay with thousands of coloured Anemones.
Those little "petals" are really tentacles, used for catching and holding food. We will use a shorter word and call them feelers. They are set in circles round the top of the Anemone, and there are many of them. The Daisy Anemone, for instance, has over seven hundred feelers. Each feeler can be moved from side to side, and can also be tucked away, out of sight and out of danger ”

“ PLANTS OF THE SHORE.
To pick a bunch of gay flowers you would look in the fields and hedge-rows, and not by the sea. Flowers, as you know, love moist soil, and not dry sand; and, like us, they prefer one food to another. Sand they do not like, and salt is a poison to them. Both of these are enemies to plant life.
Also, flowers choose sheltered spots. They do not like rough winds, and the glare of the sun shrivels them up. Yet there are plants with pretty flowers to be found by the sea, and many others with small, dull flowers. These seaside plants have to fight for their lives. ”

“ You can imagine the Periwinkle's mantle as a tube enclosing the animal's body. The mantle of the Mussel or the Oyster is in two pieces; and each half forms its own shell.
The Snail, and other one-shelled molluscs, poke their heads out of the shell when feeding or moving. Oysters and their two-shelled cousins cannot do this, for the simple reason that they have no heads!
In some places you see that the rocks at low tide are covered with Mussels. In dense black masses they cling to the rocks; and, though heavy waves bang them like so many hammers, they stick tight. ”

“ Of what use are eyes to an animal standing on its head in a small dark shell! Now and then it casts its coat (like the Crab and Shrimp) . The old coat is rolled up and thrown away outside the door.
Now comes the strangest thing of all. As a baby, the Barnacle is a free swimming creature. It has three pairs of legs, a tail, a useful mouth, and one eye. After kicking about in the sea for some time, and changing its skin, it changes its shape entirely. It now looks more like a tiny mussel. It has two little "shells," two eyes, legs, and feelers. ”

“ They live in the weed of the rock-pools, and in the wet sand. These are the Shore Crabs; the large Edible Crabs are a different kind, and live mostly in deep water.
Shore Crabs are quarrelsome little creatures; the larger ones are always ready to gobble up the smaller ones, or to snatch their food and run away with it. If you put some dead mussels or fish in a pool, you will be amused at their antics. How they scramble and fight! Crabs do not believe in "table manners."
THE CRAB.
It is their taste for waste scraps of food that makes crabs of use in the sea. ”

“ Like the foot of the Snail, it is used when the animal wishes to take a walk; but it serves another purpose too. It can be used as a sucker; and it is this which enables the Limpet to cling so firmly to its rock.
When the tide is out, the Limpet clings to the rock, its soft body tucked safely away in the shell. Its feeding time comes when the water covers the rocks once more. Then the Limpet's shell may be seen to tilt up, and a foot, and a head with feelers and eyes, come out. The Limpet crawls to the seaweed and begins to browse, using a rasp like that of the Periwinkle. ”

“ The artful Crab tears off other pieces of weed with its pincers, and attaches them to the hooks. It is another dodge, of course, to escape from enemies. The Lobster, whose picture you see, has a life-story much like that of the Crab. He, also, grows too big for his suit of armour, and casts it off in a wonderful manner, but only after a great deal of trouble. In his new suit he is very weak and soft--an easy prey to the first enemy to find him. He cannot defend himself then; he can only lie helplessly on his side, waiting for his coat to harden. ”

“ Then they are all drawn to the centre of the Anemone, carrying their prey with them; and the feelers, prey and all, are tucked out of sight.
That is the way the Anemone obtains its food. As soon as the feelers get hold of a small animal they carry it to the opening of a tube in the centre. This is the mouth, leading to the stomach. Very often the feelers, with their victim, are tucked away into the stomach, and the feelers do not appear again for some time. Is not this a strange way of eating!
Much stranger still is the way in which the food is held, and made so helpless that it cannot escape. ”

“ Finding a suitable spot, the little animal stands on its head. Then a kind of glue is formed, which fixes it for life to that place, head down. The two shells and the two eyes are now thrown off. The Barnacle quickly builds up a shelly house, and, after a life of adventure and change, becomes a fixed Barnacle for the rest of its days.
For many years people knew little of this strange animal. All its wonderful changes, and the way its body is made, tell us plainly that the Barnacle is actually first cousin to the Crab, Lobster, Shrimp and Prawn! ”

“ The Barnacle is always upside down in its home, and its twelve feathery legs are thrust out of the door at the top. They make a fine net, in which minute animals are caught and brought into the mouth below. This funny creature actually kicks its food into its mouth! If you own a magnifying glass, you can see this for yourself at the seaside.
You will not be able to see the mouth, however, which is inside the shell. It is fitted with moving parts, and feelers, like the mouth of a crab. Also, the Barnacle has a good set of teeth to grind its food. It has no real eyes, having no use for them. ”

“ We know it is an animal that lives in the sea, and dies when washed ashore. But what does it do in the sea? How does it move without legs or fins? How can it live without a head? Has it a mouth? What does it eat, and how does it find its food? ”

“ Who would expect to find millions of poisoned darts in a Jelly-fish? Who would guess that these weapons are coiled up, ready to spring out at their prey? Men have made many weapons for killing, from the bow-and-arrow to the torpedo, but none of them is more wonderful than the weapon of the Jelly-fish. ”

“ Seaweeds belong to a humble family in the world of plants, having no real roots, no flowers, and no real seeds. They can attach themselves to the stones or rocks. Along comes a great wave, and perhaps they are torn up; but this does not harm them, for they still live as they wash to and fro in the water, until they cling to another rock. Or they are thrown on the shore to die, or else to be washed back to sea by the next tide.
SEA-WEED FROND.
The Sea Lettuce or Green Laver is a common seaweed near the shore. ”

“ If we had feet like those of the Starfish, a journey up the wall of a house, over the roof, and down again, would be nothing to us. Nature gives all creatures the kind of foot which suits the life they lead. And it is hard to imagine feet more useful to the Starfish than those wonderful sucker-feet! ”

“ In time this resting-place becomes hollowed out, and the Limpet's shell fits into the groove thus made.
Limpets are useful as bait for fish. The Whelk and Periwinkle are gathered in immense numbers, and are used by us for food. Perhaps you have seen the egg-bundle of the Whelk. It contains many eggs when first laid in the sea. Each egg is as big as a pin's head. They swell in the water, until the yellowish bundle is three times as large as the Whelk that laid it. You often see the empty bundle blown by the wind along the shore. ”

“ It is a hard coat, a complete suit of armour to protect his soft body. Our picture shows the Lobster, the Crab's cousin. The Shrimp and Prawn and Lobster are relations of the Crab; these crustaceans, as they are called, are all cased up in a hard crust, which will not stretch the slightest little bit. But the Crab's body must grow! What is he to do?
At first he starves himself, and so his body shrinks inside its old shell. He loosens himself as well as he can. Soon the shell breaks across, and the Crab struggles to get free. ”

“ No doubt the Anemone is of some use to him, or he would at once pull it off. It is thought that the Anemone protects him from his enemies, the fish. Some of them would swallow the whelk shell, crab and all, but they would not eat one on which an Anemone was fixed. We are not sure that these reasons are the right ones. All we know for certain is, that a crab and an Anemone have, for some good reasons, gone into partnership.
Anemones have large families. Sometimes they have numbers of eggs; at other times their little ones come straight into the world as very tiny Anemones. ”

“ All these plants of sandy places grow like that. Sand has no food or drink to give to plants. So they send their roots out, like plants in a desert, until they find what they want. Besides food and drink, they need a firm anchor in the loose sand. The Sea Holly, with its roots deep down and far-spreading, can hold its own, though the gale tears at it and throws its sandy bed here and there.
We pass many small creeping plants as we walk in the dry sand. There is a pretty Sea Convolvulus, with its stems deeply buried. It is a cousin of the common Bindweed. ”

“ Most of the pebbles and the sand on the beach have been won from the land in the great fight. We might call them the spoils of war. Once they formed part of the solid land, the rock or cliff. Now they are loose fragments spread for mile after mile round our coast. ”

“ The Snail's shell is like the little boy's suit which is altered and made bigger as the boy grows. The crab's covering is a suit which cannot be altered. It must be thrown away, and replaced by a larger one.
The body of the shell-builder is wrapped in a soft covering, a kind of outer coat, which is called the mantle. Now this mantle is one of Nature's cleverest inventions. It is able to take the substance called lime from the food of the animal, and to use it as building stuff.
PRECIOUS WENTLETRAP.
The shell is built to fit the soft body. ”

“ They grow on the rocks, in pretty coloured tufts.
If you dive still farther, into the dark depths of the sea, you find beds of ooze and slime, and rocks and weird fishes, but no plants. Why is this? Like the land-plants, these sea-plants must have light. They cannot grow in the blackness of very deep water. Can you guess why some sea-weeds are green and others red? Those growing in the shallow water of the shore are green, like land-plants, because the sunlight reaches them. Only part of the light can pass through deep water; and so, in these shady places, the sea-weed is reddish in colour. ”