are also jointed animals, belonging to the same great division of the animal kingdom as beetles and other insects, and all these together get the general name of ARTICULATA. They might be said, therefore, to represent in the sea, the active tribes of flesheating and carrion-loving beetles on land. As a necessary condition for such a life, whether in sea or in fresh water, they are formed for aquatic respiration-in other words, they breathe by gills (or branchia.)

To the children of a sea-side village, the common or Shore crab will, in most cases, be as well known as the common frog is to children living in an inland district. On one occasion I made it the subject of a short address to a school, and as it may be interesting to other boys and girls, I shall give it here.

'I am going to tell you to-day about the Common Crab; not the large crab which we see in the markets, but the one that we find running on the sands and lurking among sea-weed; the crab that in some places is best known by the name of the "parten," and which may very properly be called the Shore crab.

'If a boy, a whiting, and a crab, were placed in sea-water and covered by it, the boy would be drowned, the fish and the crab would be safe. If, on the contrary, all were placed on the strand, the fish would die, while the boy and the crab would be uninjured. Hence it appears that the crab can live where the boy cannot live ; and that it can also live where the fish would perish. Let us see how this happens.

'You and I breathe by means of lungs, which are in that part of the body called the chest. Every breath we draw fills the chest with air, and this acts upon the blood in the lungs; this air is driven out of the chest, fresh air is inhaled, and thus the act of breathing goes on. The fish, on the contrary, does not breathe by lungs, but by gills, and they cannot act except when the water is flowing through them. We die if deprived of air; the fish dies if deprived of water in which air is contained, because it is by means of the water that it gets the air necessary for its existence. The breathing organs of the crab are quite different; so long as they are moist the crab can breathe. It has gills, which you can see in any dead crab, but these do not require a current of water

to pass through them, like those of a fish; they are wetted when the tide comes in, and this keeps them moist while the crabs are running on the sand at low-water.

'Tell me now, when you take a crab in your hand, does it feel hard or soft? It feels hard, you say. Why does it do so?

"Because it is covered with a hard crust or shell."

'Very good. Now, suppose a little crab has got this hard covering over its body, how is it ever to grow any bigger? A Snail can add a piece to its shell, and thus make its house larger when it wishes to do so. A Mussel or an Oyster can also make its shell larger by adding to it; but what is the crab to do? How is it to get out of the shell, if that be needful? and where or how is it to get a larger one? I will tell you how. The shell bursts, the crab leaves it; and, as it is now quite naked and unprotected, it keeps out of the way of danger until it has got its new suit of clothes. If any of you boys were getting a new pair of trousers, they might be too long or too short; they might have to be "taken in" a little bit, or "let out" a little bit. But the suit of clothes for the crab is sure to fit; for it is formed on the skin of the body, and moulded to the proper size in every part. Thus the crab, as it grows larger, is supplied from time to time with a new covering.

'We will now talk of another matter. Suppose that a boy should fall down in the street, and a loaded cart pass over one of his legs, crushing the bone to pieces, What would be done with him?

"The surgeon would cut off his leg, and he would have to be content with a wooden one," is the reply.

'Suppose now that you were throwing a stone into the tide, and that it fell on the leg of a crab and crushed it to pieces, What would be done for the poor crab? There is no surgeon to cut the leg off, nor to get a wooden leg made for him. The crab is, however, quite independent of such assistance; he would fling off the broken leg at the joint above the broken part, and a new leg would grow, and in time become as large and as useful in every respect as the one that was there at first.

Crabs, after they leave the egg, swim about, and are quite different in shape and appearance from what they afterwards become. Some of them are males and some are females.

'I have seen boys pelting the "parten" with stones, breaking

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off the nippers, and tormenting it in other ways. Let me ask Has the crab ever done you any harm, beyond, perhaps, giving you a bite when you were plaguing it? Has it ever done you any good? You say you don't know. Let me tell you how it has done you good; how it has done me good; how it has done good to all about us. You know many dead bodies of various kinds are thrown into the sea; many are carried into it by rivers ; many animals die there. If all those bodies were allowed to rot, and each day added to their number, the sea would become unfit for any creature to live in, and it would give out a stench that would kill those that lived on the neighbouring land. To prevent such a result, it has been wisely ordained by Him whose word has called all living things into existence, that there should be multitudes of animals to feed on dead and decaying bodies, and find their best nourishment in what would otherwise become injurious. The common Shore crab is one of those creatures; it is one of a large body of scavengers, appointed to perform a certain duty, and by doing it, becomes the means of conferring a great benefit on larger animals, and even on man himself.'

Such was my short lecture. Would that it might cause those by whom it is read to look with greater interest on the humble Shore crab and to find profitable matter for reflection in its peculiarities of structure, and the uses which they serve.

2. SEA-SCAVENGERS.-Another animal which aids in the removal of dead or decaying substances, and which belongs to the same class as the crab, but to a different division of it, is the little jumping creature known as the Sand-hopper (Talitrus locusta). A singular instance of their voracity came under my notice, on the Antrim coast, within a few miles of the Giant's Causeway. The surface of the sea was agitated, at a short distance from the land, by a shoal of fish; they were Gurnards, and were leaping and tumbling about with great activity. They had approached the beach, in order to prey on an immense shoal of young herrings, numbers of which, driven in by the larger fish, were cast up by the swell of the sea on the moist sand. They were each about two and a half inches long, and by their brightness were attractive objects, contrasted with the strand on which they lay. But they were not allowed to remain long undisturbed; hosts of Sand-hoppers made them their prey, even in some cases before life was extinct, and with such rapidity and efficiency were their operations carried

on, that delicate skeletons of the young herrings soon strewed the shore, cleansed so effectually from the flesh, that the sea-breeze was sufficient to carry them away. The Sand-hoppers in their turn became the prey of active little shore-birds, the sand-pipers— another example of the universal law "to eat and to be eaten.” How suggestive of the beneficence that dwells under all this destruction are the lines of the poet :—

"While ravening death of slaughter ne'er grew weary

Life multiplied the immortal meal as fast.
War, reckless, universal war prevail'd,
All were devourers, all in turn devour'd;
Yet every unit in the uncounted sum

Of victims, had its share of bliss, its pang,

And but a pang of dissolution; each

Was happy til! its moment came, and then

Its first, last suffering, unforeseen, unfear'd,

Closed, with one struggle, pain and life for ever."-MONTGOMERY.

The sea-scavengers, even among those that are the brethren and cousins of the shore-crab, are not limited to the beach; some of them dwell habitually in deeper water. One of these, the spinous Spider crab, after being taken prisoner in a lobster-pot, was transferred to a boat, and became the fellow-passenger of the Rev. Charles Kingsley, the gifted author of Glaucus, who in that charming little volume has thus introduced to our notice the ungainly crustacean, and his sanitary vigilance, when labouring “in his vocation :"

“In the boat, at the minute of which I have been speaking, silent and neglected, sat a fellow-passenger, who was a greater adept at removing nuisances than the whole Board of Health put together, and who had done his work, too, with a cheapness unparalleled, for all his good deeds had not, as yet, cost the State one penny. True, he lived by his business, as do other inspectors of nuisances; but Nature, instead of paying Maia Squinado, Esquire, some five hundred pounds sterling per annum for his labour, had contrived, with a sublime simplicity of economy which Mr. Hume might have envied and admired afar off, to make him do his work gratis, by giving him the nuisances as his perquisites, and teaching him how to eat them. . . . Last night, as he was sitting quietly under a stone in four fathoms' water, he became aware, whether by sight, smell, or that mysterious sixth sense, to us unknown, which seems to reside in his delicate feelers, of a palpable nuisance somewhere in the neighbourhood, and, like a

trusty servant of the public, turned out of his bed instantly, and went in search, till he discovered, hanging among what he judged to be the stems of tangle (Laminaria), three or four large pieces of stale thornback, of most evil savour, and highly prejudicial to the purity of the sea, and the health of the neighbouring herrings.

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"Nature, who can afford to be arbitrary, because she is perfect, and to give her servants irresponsible powers, because she has trained them to their work, had bestowed on him and on his forefathers, as general health inspectors, those very summary powers of entrance and removal in the watery realms for which common sense, public opinion, and private philanthropy, are still entreating vainly in the terrestrial realms; so finding a hole, in he went, and began to remove the nuisance, without waiting twenty-four hours,' 'laying an information,' serving a notice,' or any other vain delay. The evil was there, and there it should not stay; so, having neither cart nor barrow, he just began putting it into his stomach, and in the meanwhile set his assistants to work likewise. For suppose not, gentle reader, that squinado went alone; in his train were more than a hundred thousand as good as he, each in his office, and as cheaply paid; who needed no cumbrous baggagetrain of force-pumps, hose, chloride of lime packets, whitewash, pails, or brushes, but were every man his own instrument; and, to save expense of transit, just grew on Squinado's back."

The army of pigmy assistants conveyed by Squinado to the field of action was of course a little forest of growing corallines, each seeming plant containing numerous cells, every one of which was occupied by its proper inhabitant. Into the history of these tribes, however interesting, I do not at present propose to enter. Neither can I dwell on another corps of the sanitary marine police, the Star-fishes.1 These creatures are both numerous and voracious, and render good service around the coast, from the shallow shores even so far as the deep water known as the region of corallines.

3. THE HERMIT CRAB.-I shall now speak of the paguri or Hermit crabs. They are not coated all over, like the crab or the lobster, the hinder part of the body being soft, and without any shelly covering whatsoever. The hermit crab, conscious of his defenceless condition, seeks out an empty univalve shell, such as that of the whelk or the periwinkle, and into it he retreats, the

1 The "five-fingers" is one of the animals to which I refer. The sea-blubber or seanettles, though sometimes called star-fishes, belong to a different class.