LET us now leave the beach-pebbles and go down on to the rocks at low tide in order to see some of the living curiosities of the seashore. There are some seaside resorts where, when the tide goes down, nothing is exposed but a vast acreage of smooth sand, and here the naturalist must content himself with such spoils as may be procured by the aid of a shrimping-net and a spade. Wading in the shallow water and using his net, he will catch, not only the true "brown shrimp," but other shrimp-like creatures, known as "crustacea"—a group which includes also the lobsters, hermit-crabs, true crabs, and sand-hoppers, as well as an immense variety of almost microscopic water-fleas.

He will also probably catch some of the stiff, queer little "pipe-fish," which are closely related to the little creatures known as "sea-horses." Pipe-fish are very sluggish in movement, almost immobile, whilst the "sea-horse" or hippocampus—only to be taken by the dredge amongst corallines in deep water on rocky bottoms (as, for instance, in the Channel Islands)—goes so far as to curl his tail, like a South American monkey, round a stem of weed and sit thus upright amidst the vegetation. Even when disturbed he merely swims very slowly and with much dignity in the same upright position, gently propelled by the undulating vibratory movement of his small dorsal fin. The male in both pipe-fish and sea-horses is provided with a sac-like structure on the ventral surface in which he carries the eggs laid by the female until they are hatched.

a, Arenicola piscatorum. Lug-worm largely used for bait by sea-fishermen. It burrows in sea-sand and clay as the earth-worm does in soil. Half the natural size, linear.

b, Nephthys margaritacea, actively swimming. It also burrows in the sea-sand. Natural size.

c, Eunice sanguinea, a very handsome marine worm (often used for bait) which lives in clefts in the submarine rocks and also swims actively. The numerous filaments on the sides of the ringed body are the gills of a rich blood-colour. The figure is one-third of the natural size, linear.

The shrimper will probably catch also some very young fish fry—including young flat-fish about 2 inches long. If he explores the exposed surface of sand near the low-tide limit, he will find a variety of indications of burrowing animals hidden beneath. Little coiled masses like the "castings" of earth-worms are very abundant in places, and are produced by the fisherman's sand-worm, or "lug-worm" (Fig. 4, a). A vigorous digging to the depth of a foot or two will reveal the worm itself, which is worth bringing home in a jar of sea-water in order to see the beautiful tufts of branched gills on the sides of the body, which expand and contract with the flow of bright red blood showing through their delicate walls. Other sand-worms, from 2 to 6 inches long, will at the same time be turned up,—worms which have some hundred or more pairs of vibrating legs, or paddles, arranged down the sides of the body, and swim with a most graceful, serpentine curving of the mobile body (Fig. 4, b). These sea-worms are but little known to most people, although they are amongst the most beautifully coloured and graceful of marine animals. Hundreds of different kinds have been distinguished and described and pictured in their natural colours. Each leg is provided with a bundle of bristles of remarkable shapes, resembling, when seen under a microscope, the serrated spears of South Sea Islanders and mediaeval warriors. These worms usually have (like the common earth-worm) red blood and delicate networks of blood-vessels and gills (Fig. 4, c), whilst the head is often provided with eyes and feelers. They possess a brain and a nerve-cord like our spinal cord, and from the mouth many of them can suddenly protrude an unexpected muscular proboscis armed with sharp, horny jaws, the bite of which is not to be despised. These "bristle-worms," or "chÆtopods," as they are termed by zoologists, are well worth bringing home and observing in a shallow basin holding some clean sea-water.

At many spots on our coast (e.g. Sandown, in the Isle of Wight, and the Channel Islands) rapid digging in the sand at the lowest tides will result in the capture of sand-eels, a bigger and a smaller kind, from 1 foot to 6 inches in length. These are eel-shaped, silvery fish, which swim near the shore, but burrow into the soft sand as the tide recedes. They are excellent eating. We used at Sandown to make up a party of young people to dig the smaller "sand-eels," or "sand-launce." The agility and rapid disappearance of the burrowing fish into the sand when one thought one had safely dug them out, rendered the pursuit difficult and exciting. Then a wood fire on the beach, a frying-pan, fat, flour, and salt were brought into operation, and the sand-eels were cooked to perfection and eaten.

Some of the marks or small heaps of sand on the flats exposed at low tide are characteristic of certain shell-fish. The "razor-fish" (Fig. 19, b)—a very much elongated clam, or mussel, with astonishing powers of rapid burrowing—leaves a hole on the surface like a keyhole, about an inch long. It can be dug up by an energetic spadesman, but a spoonful of common salt poured over the opening of its burrow will cause it to suddenly shoot out on to the surface, when it may be picked up, and the hunter spared any violent exertion. The curious heart-urchin (Fig. 5), as fragile as an egg-shell, and covered with long, closely-set spines like a brush, is often to be found burrowing in the sand, as well as the transparent, pink-coloured worm known as Synapta, in the skin of which are set thousands of minute calcareous anchors hinged to little sculptured plates. These burrowers swallow the sand and extract nutriment from stray organic particles mixed in it.

The mere sand-flat of the low tide is not a bad hunting ground; but the rock pools, often exposed when the tide is out, and the fissures in the rocks and the under surfaces of slabs of rock revealed by turning them over—are the greatest sources of varied delight to the sea-shore naturalist. It is well to take a man with you on to these rocks to carry your collecting bottles and cans, and to turn over for you the larger slabs of loose stone, weighing as much as a couple of hundredweight. The most striking and beautiful objects in these rock pools are the sea-anemones (Fig. 6 and Frontispiece). They present themselves as disk-like flowers from 1 to 5 inches in diameter, with narrow-pointed petals of every variety of colour, set in a circle around a coloured centre. The petals are really hollow tentacles distended with sea-water, and when anything falls on to them or touches them they contract and draw together towards the centre. The centre has a transverse opening in it which is the mouth, and leads into a large, soft-walled stomach, separated by its own wall from a second spacious cavity lying between that wall and the body wall, and sending a prolongation into each tentacle. The stomach opens freely at its deep end into this second "surrounding" chamber, which is divided by radiating cross walls into smaller partitions, one corresponding to each tentacle. The nourishing results of digestion, and not the food itself, pass from the stomach into the subdivided or "septate" second chamber. There is thus only one cavity in the animal, separable into a central and a surrounding portion.

In this respect—in having only one body cavity—sea-anemones and the coral-polyps and the jelly-fishes and the tiny freshwater polyp or hydra, and the marine compound branching polyps like it—agree with one another and differ from the vast majority of animals, such as worms, sea-urchins, star-fishes, whelks, mussels, crustaceans, insects, spiders and vertebrates (which last include fish, reptiles, birds, and mammals). These all have a second chamber, or body cavity, quite shut off from the digestive cavity and from the direct access of water and food particles. This second distinct chamber is filled with an animal fluid, the lymph, and is called the "Coelom" (a Greek word meaning a cavity). These higher animals, which possess a coelom as well as a gut, or digestive cavity, are called "Coelomata," or "Coelomocoela," in consequence; whilst the sea-anemones, polyps, and jelly-fish form a lower grade of animals devoid of coelom, but having the one cavity, or gut, continued into all parts of the body. Hence they are called "Coelentera," or "Enterocoela," words which mean that the cavity of their bodies (Greek coel) is made by an extension of the gut, or digestive cavity (Greek enteron). The higher grade of animals—the Coelomocoela—very usually have a vascular system, or blood-vessels and blood, as well as a coelom and lymph, and quite independent of it; also some kind of kidneys, or renal excretory tubes. Neither of these are possessed by the sea-anemones and their allies—the Enterocoela—but they have, like higher animals, a nervous system and also large ovaries and spermaries on the walls of their single body cavity, which produce their reproductive germs. These pass to the exterior, usually through the mouth, but sometimes by rupture of the body wall.

All "one-cavity" animals, the Enterocoela or Coelentera, produce peculiar coiled-up threads in their skin in great quantity—many thousands—often upon special warts or knobs. These coiled-up threads lie each in a microscopic sac; they are very delicate and minute and carry a virulent poison, so that they are "stinging" threads. Excitement of the animal, or mere contact, causes the microscopic sac to burst, and the thread to be violently ejected. The sea-anemones, jelly-fish, and polyps feed on fresh living animals, small fish, shrimps, etc., and catch their prey by the use of these poisonous threads. Some jelly-fish have them big enough to act upon the human skin, and bathers are often badly stung by them. The commonest jelly-fish do not sting, but where they occur a few of the stinging sort are likely to occur also. Even some sea-anemones can sting one's hand with these stinging threads. One sea-anemone (known as "Cerianthus"), occasionally taken in British waters, makes for itself a leathery tube by the felting of its stinging threads, and lines its long burrow in the sand below tidal exposure in this way.

The sea-anemones are very hardy, and they are wonderfully varied and abundant on our coasts. Some sixty years ago a great naturalist, who loved the seashore and its rock-pools enthusiastically, Mr. Philip Henry Gosse, father of Mr. Edmund Gosse, the distinguished man of letters, described our British sea-anemones, and gave beautiful coloured pictures of them. One of these I have taken for the frontispiece of this volume, and some of the outline figures of marine animals in these chapters are borrowed from a marvelously complete and valuable little book by him—now long out of print—entitled "Marine Zoology." His books—of high scientific value—and his example, made sea-anemones "fashionable." London ladies kept marine aquariums in their drawing-rooms stocked with these beautiful flowers of the sea. They were exhibited in quantity at the Zoological Gardens in Regent's Park, and it is by no means a creditable thing to our London zoologists that neither these nor other marine creatures are now to be seen there. At a later date public marine aquaria were started with success in many seaside towns,—Brighton, Scarborough, Southport, etc.—and a very fine one was organized in Westminster and another at the Crystal Palace. It is an interesting and important fact, bearing on the psychology of the British people, that most of these charming exhibitions of strange and beautiful creatures from the depths of the sea were very soon neglected and mismanaged by their proprietors; the tanks were emptied or filled with river water, and the halls in which they were placed were re-arranged for the exhibitions of athletes, acrobats, comic singers, and pretty dancers. These exhibitions are often full of human interest and beauty—but I regret the complete disappearance of the fishes and strange submarine animals. I have some hope that before long we may, at any rate in the gardens in the Regent's Park, see really fine marine and fresh-water aquaria established, more beautiful and varied in their contents than those of earlier days.

a, Sagartia bellis, the daisy anemone, viewed from above when fully expanded.

b, Bunodes crassicornis, half expanded; side view.

c, Anthea cereus. The tentacles are pale apple-green in colour, tipped with mauve, and cannot be completely retracted.

d, Actinia mesembryanthemum. The disk of tentacles is completely retracted. This is the commonest sea-anemone on our South Coast, and is usually maroon colour, but often is spotted like a strawberry.

There are four kinds of sea-anemones which are abundant on our coast. They adhere by a disk-like base to the rocks and large stones, and have the power of swelling themselves out with sea-water (as have many soft-bodied creatures of this kind), with all their tentacles expanded. They have, in that condition, the shape of small "Martello" towers, with their adhesive disk below and the mouth-bearing platform above, fringed by tapering fingers; and they can, on the other hand, shrink to a fifth part of their expanded volume, drawing in and concealing their tentacles, which are in some kinds perforated at the tip. One common on the rocks at Shanklin and other parts of our South Coast, but [Pg 85]
[Pg 86]not on the East Coast, has very abundant, long, pale green tentacles, which are tipped with a brilliant peach colour, and it is peculiar in not being able to retract or conceal this beautiful crown of snake-like locks, reminding one of the Gorgon Medusa. It is known as Anthea cereus (Fig. 6, c). Many of them are known by the name "Actinia," and the commonest of all (Fig. 6, d) is called "Actinia mesembryanthemum," because of its resemblance to a fleshy-leaved flower of that name which grows on garden rockeries—sometimes called the "ice-plant." This one is of a deep maroon colour, rarely more than an inch and a half across the disk. The adhesive disk is often edged with bright blue, and small spherical tentacles, of a bright blue colour, are set at intervals outside the fringe of longer red ones. This anemone lives wonderfully well in a small glass basin or in an aquarium holding a gallon of sea-water, which is kept duly aerated by squirting it daily. One lived in Edinburgh for more than fifty years, in the possession first of Sir John Dalyell, and then of Mr. Peach. She was known as "Granny," and produced many hundreds of young in the course of years. This species is viviparous, the young issuing from the parent's mouth as tiny fully-formed sea-anemones, which immediately fix themselves by their disks to the glass wall of their habitation. Anemones kept thus in small aquaria have to be carefully fed; bits of the sea mussel (of course, uncooked) are the best food for them. This and many other kinds are not absolutely stationary, but can very slowly crawl by means of muscular movements of the adhesive disk. There are kinds of sea-anemones known which spend their lives floating in the ocean; they are thin and flat. Others adhere to the shells of hermit crabs and even to the big claws of some crabs, and profit by the "crumbs" of food let fall by the nippers of their host. A very handsome and large sea-anemone is common on the East Coast, and is known as "crassicornis" (its generic name is Bunodes). When distended it measures as much as 4 inches across (Fig. 6, b). I have one at this moment before me, expanded in a bowl of sea-water. The tentacles are pale green or grey, banded with deep red, and the body is blotched with irregular patches of red, green, and orange. It attaches fine pebbles and bits of shell to the surface of the body.