Twice in every twenty-four hours the waters of the ocean ebb and flow. Twice only in each month, however, do the spring-tides occur. For there are few dangers that the ardent student of nature would not encounter. Lord Bacon tells of a certain bishop who used to bathe regularly twice every day, and on being asked why he bathed thus often, answered, 'Because I cannot conveniently bathe three times.' The zoologist, like the 'right reverend father' alluded to, would willingly undergo what appears to others much hardship and trouble, not only once or twice, but even three times daily, in pursuit of his favourite studies, did Nature but offer the kind convenience.

On these occasions the zoologist can pursue his researches at the shore, at a distance beyond the usual tidal line. Numerous boulders and rock-pools, during many days covered by the sea, being then laid bare and exposed to his eager, searching hands and eyes, he is frequently able to discover many rare objects, or, at least, common ones revelling in almost giant-like proportions, and wonderful profusion.

The Soldier or Hermit-Crabs (to an account of whom we intend to devote this chapter), offer a most remarkable proof of this. Occupying the centre of a rocky excavation, I have repeatedly found several dozen of these comical creatures, each inhabiting the cast-off shell of a defunct Whelk (Buccinum undatum), which measured not less than five or six inches in length. To my surprise these aldermanic crustaceans possessed no companions of a smaller growth; while at a few yards nearer shore, as many shells would be found congregated together as in the more distant pool,—the largest, however, being no bigger than a damson, while the smallest might be compared to an infantile pea, or cherry-stone.

I cannot explain this appearance otherwise, than by supposing that the Anomoura become prouder, or, it may be, more cunning, as they grow older, and, having arrived at their full development, they fit themselves with their final suit; thereafter, in a spirit of aristocratic exclusiveness, they retire to fashionable subaqueous residences, distant as far as possible from the homes of the canaille, who inhabit the common, littoral boundaries of the shore.

The peculiarity, to which I alluded, of the Anomoura occupying shells that have formerly belonged to other animals, is so strange that some writers have not hesitated to express doubt upon the subject. This denial of a fact, which can so readily be proved, is one of the 'curiosities of literature.' Swammerdam, a Dutch naturalist contemptuously observes, 'What an idle fable that is which is established even among those who study shell-fishes, when they show some kind of the crab kind in their museums, adding at the same time, that they pass from one shell to another, devour the animals that lived in those shells, and keep them for their own habitations. They dignify them with the high-sounding names, and additions, as Soldiers, Hermits, and the like; and thus, having no experience, they commit gross errors, and deceive themselves, as well as others, with their idle imaginations.'

That there is nothing mythical in the matter can easily be made apparent to any person who chooses to visit the sea-shore. At such locality he need have no difficulty in recognising the Hermit-Crab, or meeting with numerous specimens for examination. Supposing such a one is at a rock-pool, and, moreover, that he knows by sight the Buckie (periwinkle), and Common Whelk, he will probably in such case be aware that the animals occupying these shells are snail-like in construction, and that their locomotion is consequently slow and formal. If, therefore, when peering into any pool he sees the Buckie, for instance, apparently change its nature, and instead of

'Dragging its slow length along,'

scamper off suddenly, or roll over and over from the top of an eminence to the bottom, he may rest assured that the original inhabitant has departed, and that its place is occupied by a Lobster-Crab.

The cause of his strange peculiarity I will briefly explain.

In the true Lobster the tail forms a most valuable appendage. In the tail the principal muscular power of the animal is seated; and by means of it, too, the animal is enabled to spring to a considerable distance, and also to swim through the water at will. This important organ is well protected by a casing consisting of a 'series of calcareous rings, forming a hard and insensible chain armour.'

In the Lobster-Crab there is no such arrangement. 'The abdominal segment of this singular animal, instead of possessing the same crustaceous covering as the rest of his body and claws, is quite soft, and merely enveloped in a thin skin. To protect this delicate member from the attacks of his voracious companions, the poor Pagurus is compelled to hunt about for some Univalve, such as a Whelk or Trochus, and having found this, he drops his tail within the aperture and hooks it firmly to the columella of the shell. Why Providence has doomed the poor Hermits to descend to such physical hypocrisy, and clothe themselves in the left-off garments of other animals, it is not easy to conjecture. No doubt, besides the defence of their otherwise unprotected bodies, he has some other object of importance in view. Perhaps they may accelerate the decomposition of the shells they inhabit, and cause them sooner to give way to the action of the atmosphere; and as all exuviÆ may be termed nuisances and deformities, giving to these deserted mansions an appearance of renewed life and locomotion, removes them in some sort from the catalogue of blemishes.'

Professor Jones, when treating of this class of animals, forcibly remarks that 'the wonderful adaptation of all the limbs to a residence in such a dwelling, cannot fail to strike the most curious observer. The ChelÆ, or large claws, differ remarkably in size, so that when the animal retires into its concealment, the smaller one may be entirely withdrawn, while the larger closes and guards the orifice. The two succeeding pairs of legs, unlike those of the Lobster, are of great size and strength, and instead of being terminated by pincers, end in strong-pointed levers, whereby the animal can not only crawl, but drag after it, its heavy habitation. Behind these locomotive legs are two feeble pairs, barely strong enough to enable the Soldier-Crab to shift his position in the shell he has chosen; and the false feet attached to the abdomen are even still more rudimentary in their development. But the most singularly altered portion of the skeleton is the fin of the tail, which here becomes transformed into a kind of holding apparatus by which the creature retains a firm grasp of the bottom of his residence.'

So great is the power of the animals to retain hold of their shell, and so intense their dislike to be forcibly ejected therefrom, that they will often allow their bodies to be pulled asunder, and sacrifice their life rather than submit to such indignity. This fact I have proved on sundry occasions. But supposing a crab to have taken a fancy to a shell, occupied by some brother Pagurus, (a circumstance of frequent occurrence), he quickly proceeds to dislodge the latter. Curious to state, this process never seems attended with any fatal result.

When watching the operation, it has appeared to me as if the crab attacked preferred to yield rather than be subjected to continuous annoyance, and the discomfort of keeping for so long a time buried within the inner recesses of his dwelling.

The contrast in appearance of the Hermit-Crab when seated in his shell, and crawling about minus such appendage, is great indeed.

This the reader will readily perceive by examining the Illustrations on Plate 4, which are drawn from nature, and are truthful portraitures of this singular creature.

I have already mentioned the extreme difficulty there is in expelling a Lobster-Crab. This, be it understood, applies only to the animal in good health; for no sooner does he feel sick than he instantly leaves his shell, and crawls about in a most pitiable plight. He sometimes becomes convalescent again by being placed solus in some fresh water, or laid out in the air for a few moments. But he ought, on no account, when in a sickly condition, to be allowed to hide himself beneath any pieces of rock or shadow of the AlgÆ.

If he is out of sight, be sure not to let him be out of mind; for, should he die in the tank, and his body be allowed to remain for any length of time, he will very soon afford you full proof that such toleration on your part is anything but pleasant.

Although, as already stated, this animal cannot be drawn out of his shell except by extreme force, the object can easily be obtained by aid of strategy. Having been for some time at a loss how to give certain young visitors a sight of the Hermit-Crab in his defenceless state, I, by accident, hit upon the following simple plan:—

With a piece of bent whalebone I lifted up a Pagurus, shell and all, and allowed the latter to drop upon the outer row of the tentacula of an Actinia, which quickly stuck fast to the intruding object. The crab at first did not seem fully alive to his critical position. He popped out of his shell and looked unsuspectingly around, until catching sight of my face, he instantly retired from view with a casket-like snap. In a minute he was out again, and this time prepared to change his position. For this purpose he gave several successive pulls, but finding all his efforts to remove his carriage unavailing, he unhooked his tail and scrambled down among the pebbles. My purpose was thereby gained, for the next moment he was resting in the palm of one of my juvenile friends, who seemed quite delighted with his prize. Twice afterwards, being in a mischievous mood, I gave the crab a fright in the way just mentioned; but it was quite evident, that what might be sport to me was death to him, for he was both annoyed and alarmed at my procedure. Even when guiltless of any intention of touching the creature, if I merely showed him the cane he immediately hobbled away at the utmost rate of speed he could muster. On several occasions I followed after and brought him back to the edge of the tank, although such conduct met with his strongest disapproval, and caused him for some time to sulk beneath an arch-way of rock work, away from the reach of vulgar eyes.

Upon the side and near the base of my tank a fine specimen of the Limpet was at one time attached. From the centre of its shell a forest of sea-grass waved gracefully, shadowing a large colony of Barnacles thickly clustered beneath. Soon the Patella decided upon taking its usual morning stroll in search of food, a task of little difficulty, standing as the animal already did upon the margin of a broad meadow, richly coated with a verdant growth, composed of the infant spores of the Ulva. Slowly moving along, the Patella, with its riband-like band of teeth, swept off the luscious weed in a series of graceful curves, thus making an abundant and healthful meal. Before proceeding far, however, he was forced to bear the weight of a Soldier-Crab, who had most unceremoniously climbed upon his back, and taken up a position at the base of the latissima fronds.

There seemed so much nonchalance about the Pagurus that I determined to watch his movements, and, if possible, to see how he would manage to descend from a position which, if the mollusc continued his mowing operations, would soon be unenviably high.

In about an hour the Limpet had reached the level of the water in the aquarium, and there took up his abode for the night. Next day and the next there was no change of situation. The crab now began evidently to perceive the danger of the position in which he was placed, for he constantly moved to and fro, and peered over into what must have seemed to him an unfathomable abyss.

While I stood, the Patella made a sudden movement of its shell—so sudden, indeed, as to startle its companion, who quickly put out his claws to save himself from falling. Unfortunately, in his spasmodic gesture he allowed the tip of one of his claws to intrude under the edge of the conical canopy, thus, in fact, pricking the fleshy 'mantle' of the animal within, who instantly, of course, glued itself to the glass with immoveable firmness. I suppose the same thing must have frequently occurred without my knowledge, for after a lapse of several days the Pagurus and his bearer were still in the same spot. I felt a growing alarm for the continued health of the Hermit-Crab, from the fact of its being poised so directly over the ever-expanded tentacles of a large Anemone. To prevent any mishap, I went to lift his crabship, with a view of transferring him to a place of safety, when, no sooner did he perceive the advancing forceps, than he rushed into his shell with a sudden and audible 'click,' forgetting for the moment that he stood on such ticklish ground. The consequence was that, seeking to avoid Scylla, he fell into Charybdis. In other words, he dropped plump upon the well-gummed tenter-hooks of the Crassicornis, which instantly closed and engulphed its prize. In vain did I endeavour with all speed to pick out the devoted Pagurus. The more I tried, the more firmly did the Actinia hold him in its convulsive grasp.

With extremely few exceptions, the Hermit-Crabs are always found to be a prying, prowling, curious class of animals, and are ever, like the husband of the fair Lady Jane—

'Poking their nose (?) into this thing and that.'

They will turn over each shell and pebble that comes in their way, and examine it with profound attention, or industriously climb up and roll down hillocks and trees in the shape of small rocks and sea-weeds, much to their danger.

I once possessed a Hermit-Crab, whose voracious movements afforded considerable amusement to myself and my friends. My Diogenes—or, as the Cockney news-boys used to pronounce the now extinct comic periodical, Dodgenes—on a certain occasion had climbed up a segmentally cut frond of Irish Moss. On reaching the topmost point, his weight became too great for the weed to bear; so, finding he was losing his equilibrium, in great alarm he made a clutch at the first object that stood near, in order to save him from falling.

A mussel was moored hard by, to the side of the vase by means of its silken byssus threads, and upon this friendly bivalve the Pagurus leaped by aid of his long taper legs. Unluckily the shell of the Mytilus was open, and the crab unwittingly thrusting his toe within the aperture, the intruding object was of course instantly gripped by the mollusc. This accident put him in a terrible fright. His gestures were most excited, and no wonder. Let the reader fancy himself hanging on to a window sill, at a height say of twenty feet from the ground, with the sash-frame fixed on his hand, and a huge iron foot-bath, or some such object, attached to the lower part of his body, and he will have a tolerably correct idea of the painful position of our crustacean friend.

After curling and uncurling his tail, and trying several times in vain to throw his tub upon the valve of the mussel, he released hold of his encumbrance, and allowed it to drop. Although still hanging, he had no difficulty in rolling up his 'continuation,' and elevating his body to the walls of his prison. Once again upon solid ground, he laboured hard to get his leg free. But unsuccessful in his efforts, he adopted another course, and snapped it off in a rage.

Scarcely, however, was the act of mutilation finished, when the stupid animal apparently seemed anxious to recover his lost toe, (which I may mention, had in reality fallen down among the pebbles).

After scraping, then resting, and scraping again, many successive times, he at last succeeded in diving the points of his largest claw into the chasm formed by the gaping mollusc. Of course, the member was held as if by a powerful vice. Very soon his courage deserted him, and he seemed to wait and weep despairingly for fate to release him from the sad predicament into which he had foolishly fallen. Alas! he little knew the singular part that fickle fortune had doomed him to play,—to become, if I may so term it, a kind of Prometheus in the tank.

My pack of fishes, having been on short rations for several days, had become exceedingly ravenous, and consequently were keeping a sharp look-out for scraps. Hence their intense delight on catching sight of the devoted 'Dodgenes' can readily be imagined. Such a delicious morceau was perfectly irresistible:—

At it they went, 'tooth and nail,' First one and then another tore away a mouthful, until in the twinkling of an eye, almost, the martyr crab was left forlorn and dead—

'A remnant of his former self.'

During the early portion of last year I had a Hermit-Crab inhabiting a pretty Purpura, whose shell I wished to sketch as an illustration, it being of peculiar form and colour. On going to the tank I discovered that Pagurus had most apropos vacated his turbinated cot, apparently in consequence of his feeling rather squeamish. Thinking he might perhaps presently recover, or pick up another dwelling, I hesitated not to abstract the shell, in order to make the required drawing. I had not been occupied with my task for more than five minutes, when my attention was attracted by a great excitement and clatter pervading the tank. A hasty glance within the vessel sufficed to explain the cause of the hubbub.

The brief domestic drama of which I was a spectator, with its somewhat singular denouement, I will now proceed to unfold for the reader's entertainment. It conveys a good lesson in natural history, and also exhibits a striking example of life beneath the waters.

The Blennies, I may state, had become very voracious, pugnacious, and audacious; nothing seemed safe from their attacks. I had begun to feed them on the Cardium edule and Mussel, but such diet, after a time, only served to whet their appetite, which certainly appeared to 'grow by what it fed on,' for they darted about through the water in all directions, searching, as I suppose, for other dainties. These efforts were unsuccessful, until they caught sight of the plump, undefended portion of the body of their companion, the Hermit-Crab, who had just left his shell, as above stated.

The sight of such a feast must have (figuratively speaking) made their 'mouths water,' One after another these rascally fish dodged round the crustaceous victim, and gripped, and shook his 'continuation' with extraordinary violence. In vain did the crab try to act on the defensive; all his efforts to retaliate were ineffectual, and in this instance it might be truly said that 'might' overcame 'right.' He ran to and fro in great distress, scraping the pebbles and shells about (thus partly creating the clatter that I had heard while sketching), in the hope that he might find an empty univalve in which to deposit his mutilated carcase. When almost breathless and exhausted, he discovered a worn-out Wentletrap, and strove to lift his quivering body into the aperture, alas! without success. His strength failed him, and he fell dead at the very threshold of his new-found home.

While watching thus far the above transaction, the writer felt almost inclined to waver in the faith he had long held with others, namely, that fishes and other marine animals are insensible to pain. But the movements of this poor Hermit-Crab were as indicative of severe suffering as anything he ever witnessed in bird or quadruped.

Wishing to examine the remains of the crab, I stepped aside for a few moments to procure my forceps, but when I again reached the vase, to my intense surprise the defunct animal was nowhere to be seen! I could only account for so singular a circumstance by supposing some of the larger crustaceans had taken advantage of my absence to complete the work of destruction, and therefore took no further notice of the matter at the time.

I had often wished that some of my finny pets would deposit their spawn in the tank, and felt very anxious, if such an event did take place, that I might be near to witness it. But I was most anxious to watch the gradual development of the ova, and, if practicable, to become the fond owner of a host of infant 'fishlings.'

Guess the thrill of pride, then, which ran through my veins when, on peering into my mimic rock-pool, after a brief absence from home, I observed the largest of my Blennies to be apparently in an 'interesting condition.' I watched and petted her many times daily, and fed her with every suitable dainty that could be thought of. Sometimes I took her in the palm of my hand, and with a fine camel-hair pencil stroked her glossy back. This operation evidently gave great delight to the little beauty; and after a while, when my hand was laid in the water, she gently floated off into her native element with almost swan-like grace.

The law of nature being the same with this fish as with the Stickleback, I knew the nest, if there was to be one at all, should be built by the male. But as I could not detect any specimen of the 'sterner sex' among my pack, and there being no signs of preparation for the grand event about to take place, I felt in a manner compelled to carry out the nidifying task in my own humble way. Of course, I gave up all idea of 'weaving' a nest with bits of weed, stones, and marine glue; nor was such a style of structure a desideratum in the present instance, wanting, as I did, to take notes, in Paul Pry fashion, of the minutest particular that might occur within the building. The following was the plan I adopted. First was procured the exquisitely formed valve of a large Pecten, the interior of which was white and beautifully irridescent. This pretty cot, I said to myself, shall serve as a chamber for my protÉgÉ. The shell being deposited behind a piece of rock, in such a position that its side rested against the surface of the glass, I was thus enabled to watch what was going on within. Some fronds of sea-weed were trained around so as to form a kind of drapery. The Blenny, I am quite certain, knew perfectly well that all this care and preparation was on her account, for nearly the whole of each day she spent in the novel apartment extemporized for her accommodation. After a week had elapsed, she grew uneasy and pettish, was ever snapping at her companions, and hunting them about in all directions. On one occasion, however, she seemed to be uneasy, now clashing round the rock, then darting to the top of the tank, and down again upon the pebbles. Scores of times these movements were repeated, until I felt alarmed for her safety, and annoyed at my inability to relieve her sufferings. But aid from me being impossible, I felt compelled, though very unwillingly, to allow nature to take its course.

On looking into the aquarium one morning, I observed some strange object protruding from the fish. The little creature, too, on catching sight of me, came to the side of the tank, near to where I stood, and by her movements asked me, as plainly as any dumb animal could ask, to give her my assistance. After a few minutes spent in a 'brown study', I resolved to grant her petition, and immediately setting to work, drew from her—what? what do you suppose, reader? In truth neither more nor less than the body, head, and long antennÆ of the 'martyr' Hermit-Crab! whose late sudden disappearance was now fully accounted for.

There are ten British species of Lobster-Crab, but one only, P. Bernardhus, to which the reader has been introduced, is common to our shores.

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