In the tank, it is not particularly interesting; it grovels on the bottom among the pebbles, and will cover its body with the sediment so far as it is able; where it lies for hours, watching upward. Doubtless this is its habitual mode of obtaining its food; lying motionless in wait, nearly concealed, the eyes and the mouth both opening upwards, so that the former can observe, and the latter seize, any vagrant crustacean, or annelid, or young fish-fry that unsuspectingly swims within reach. Its motions when its energies are aroused are rapid, sudden, and forcible; and it probably rarely misses its victim when it makes its snap; while the multitude of minute creatures that roam continually over every part of the sea-bottom give no lack of opportunities for the exercise of its instincts. He fares sumptuously, no doubt.
Here is in the drag a specimen of an interesting tribe of fishes. It is the young of the common Thornback, a little thing about five inches in width, and in its infantile grace and beauty much more attractive than the older ones we are accustomed to see on the fishmonger’s table. It flaps and flutters in impatience at being dragged out of its element, and exposed to ungenial air: we will quiet its anxiety by lifting it into yonder shallow rock-pool. Now watch it. How easily and gracefully it glides around its new abode, moving along by an undulation of the edges of the broad pectoral fins, a movement which Yarrell describes as something between flying and swimming. Now it lies still on the sand-floor of the pool, motionless, save that the two oval orifices just behind the eyes are constantly opening and closing, by the drawing across each or back, of a film which exactly resembles an eyelid, and which on examination with a lens we see to be edged with a delicate fringe. The action is so closely like the winking of an eye, that an observer seeing the fish for the first time might readily suppose the orifices to be the organs of vision. They are, however, outlets of the gills, called spiracles; the ordinary gill-apertures are five on each side, placed semi-circularly on the inferior surface of the body, as you see when I turn the fish on its back, a demonstration which it resents and resists with all its might: these upper orifices communicate with the gill-chambers by canals, and you may see the water now and then strongly driven out of them.
The eyes are these knobs just in front of the spiracles; or rather these are the orbits, the pupil looking sideways and somewhat downward. If you use the lens again, you perceive that there is a singular protection to the pupil in the form of a fan-like array of about a dozen stiff points arching over it.
The general form of the fish is beautifully symmetrical; it is nearly a rhomboid, with the two front sides slightly excavated, and the two posterior sides convex. At the point where these latter unite, there are two smaller fins (the ventrals), and the body is continued very slender to a considerable length, tapering to a point, near which two upright dorsals are placed. The pectorals, as in all this tribe, are of enormous size, forming the lateral angles of the rhomboid, and extending in front of the head to the tip of the snout.
The colours are beautiful, but not at all gaudy. A warm olive brown is the ground hue, on which numerous roundish black spots, with softly blending outlines, are set in symmetrical patterns, and there are also rows of pale spots. This combination of hues is elegant. The slender prolongation of the body is edged with a narrow stripe of pure white. The colour of the whole under surface is richly iridescent, like mother-of-pearl.
At present we see only a few of the curved spines appearing, chiefly in the vicinity of the eyes, which in the adult become so conspicuous and remarkable; being something like strong rose-spines, each set on an oval button of bone, imbedded in the skin.
Another draught presents us with the Fifteen-spined Stickleback,[61] a little fish, remarkable for its form, but much more so for its habits. It is ordinarily about five or six inches in length, very slender and lithe, from which circumstance, combined with a protrusion of the jaws, which gives it a sinister expression, it is on some parts of the coast called the Sea-Adder. The lower jaw projects considerably beyond the upper, which indicates that the fish habitually takes its food from a point above the level of its own body. The dorsal and anal fins are high and short, so as to form, when erected, nearly equal-sided triangles; but the former is preceded by fifteen minute sharp erectile spines, each of which has its own little membrane, and all together represent the spinous portion of the dorsal fin in such fishes as have but one, as the Blennies, or the first dorsal in such as have two, as the Weevers. The caudal is narrowly lozenge-formed, as ordinarily carried, but becomes fan-like when expanded. The colours are deep sepia, or olive-brown, cast into streaks and irregular clouds, on the sides, where they are interrupted by white, and by a rich golden yellow, that extends over the inferior surface: the dorsal and anal fins are white, each crossed by a broad conspicuous band of brown; the eyes have golden irides.
We frequently see this attractive little fish hovering about the long tufts of wrack and tangle that hang from perpendicular rocks, and from the quays and wharves of our harbours. It diligently hunts about for its minute crustacean prey, in picking off which it assumes all varieties of position “between the horizontal and perpendicular, with the head downward or upward,” thrusting its projecting snout into the tufted weed, and snatching its morsel with a sudden jerk.
It is, however, in its domestic relations that this little fish presents itself in the most interesting aspect. It was known ages ago to Aristotle, that some fishes are in the habit of forming nests, in which they deposit their eggs, and bring up their young with a parental care not inferior to that of birds. Until lately, however, this fact was supposed to be fabulous; and fishes were believed by the greatest masters of modern zoology to be utterly destitute of the parental instinct. Recent research has in this, as in so many instances, proved the exactitude of the old Stagyrite’s knowledge, and we now know that several fishes of different families nidificate. The Sticklebacks, most of which inhabit in common our marine and fresh waters, are remarkable for the manifestation of this faculty, as was first shown by Mr. Crookenden, of Lewisham, in 1834, and as has since been proved, with many interesting details, by Mr. A. Hancock and Mr. Warington. Our Sea-Adder, which is exclusively marine, was first ascertained to be a nest-builder by the late Dr. George Johnston, who mentioned the fact in the “Transactions of the Berwickshire Naturalists’ Club” in 1839. But the most interesting account is that of Mr. R. Q. Couch, who noticed the facts on the coast of Cornwall, and thus records them in a paper read before the Royal Institution of that county:—
“During the summers of 1842 and 1843, while searching for the naked mollusks of the county, I occasionally discovered portions of sea-weed and the common coralline (Corallina officinalis) hanging from the rocks in pear-shaped masses, variously intermingled with each other. On one occasion, having observed that the mass was very curiously bound together by a slender, silken-looking thread, it was torn open, and the centre was found to be occupied by a mass of transparent, amber-coloured ova, each being about the tenth of an inch in diameter. Though examined on the spot with a lens, nothing could be discovered to indicate their character. They were, however, kept in a basin, and daily supplied with sea-water, and eventually proved to be the young of some fish. The nest varies a great deal in size, but rarely exceeds six inches in length, or four inches in breadth. It is pear-shaped, and composed of sea-weed or the common coralline as they hang suspended from the rock. They are brought together, without being detached from their places of growth, by a delicate opaque white thread. This thread is highly elastic, and very much resembles silk, both in appearance and texture: this is brought round the plants, and tightly binds them together, plant after plant, till the ova, which are deposited early, are completely hidden from view. This silk-like thread is passed in all directions through and around the mass, in a very complicated manner. At first the thread is semi-fluid, but by exposure it solidifies; and hence contracts and binds the substance forming the nest so closely together that it is able to withstand the violence of the sea, and may be thrown carelessly about without derangement. In the centre are deposited the ova, very similar to the masses of frog-spawn in ditches.
“Some of these nests are formed in pools, and are consequently always in water: others are frequently to be found between tide-marks, in situations where they hang dry for several hours in the day; but whether in the water or liable to hang dry, they are always carefully watched by the adult animal. On one occasion I repeatedly visited one every day for three weeks, and invariably found it guarded. The old fish would examine it on all sides, and then retire for a short time, but soon returned to renew the examination. On several occasions I laid the eggs bare, by removing a portion of the nest; but when this was discovered, great exertions were made to re-cover them. By the mouth of the fish the edges of the opening were again drawn together, and other portions torn from their attachments and brought over the orifice, till the ova were again hid from view. And as great force was sometimes necessary to effect this, the fish would thrust its snout into the nest as far as the eyes, and then jerk backwards till the object was effected. While thus engaged it would suffer itself to be taken by the hand, but repelled any attack made on the nest, and quitted not its post so long as I remained; and to those nests that were left dry between tide-marks, the guardian fish always returned with the returning tide, nor did they quit the post to any great distance till again carried away by the receding tide.”
It is worthy of note that the newly-hatched young from these nests were so unlike the full-grown Stickleback, and so like the common smooth Blenny, that Mr. Couch concluded that there had been some error in his observation, and that the nest truly belonged to the latter fish. Further research, however, proved that the Stickleback was indeed the parent; and the transition from the infantile Blenny-like outline of the face, high, bluff, and almost perpendicular, to the true Stickleback outline, long, slender, pointed, with the far-projecting lower jaw, is something remarkable.
But now the tide has reached its lowest mark; and as we wander over the wet sand at its very verge, our attention is attracted by every tiny object that breaks the uniform level, even at a considerable distance. Some of these are worm-casts thrown up by busy Annelids, working away in the sand to reach a lower and therefore a wetter level, as the upper stratum dries in the sun. But others are Crabs, of two or three species. One of them is the somewhat uncommon and very beautiful Portumnus variegatus, of which a great number are left by the sea, but all of them dead; some of them, however, from their freshness, only recently defunct. The shape of the carapace, or body-shell, is very elegant, and the colours, though sober—a light drab, mottled and pencilled with pale lilac—are pleasing: the hindmost pair of feet terminate in thin swimming-plates, but they are narrow, and exhibit the natatory character in only a subordinate degree.
Other Crabs are alive and active, though, to be sure, in a somewhat sluggish way. Here we catch sight of a slight movement in the wet sand, and, stooping, we perceive a pair of antennæ, much beset with short bristles, projecting from the surface. They wag to and fro, and presently up pushes a shelly head, with its pair of stalked and jointed eyes, and two tremendously long angular arms, furnished with awkward-looking nippers at their extremities. Another effort, and the whole Crab emerges from his sandy burrow, and displays his pale buff-coloured shell, wrinkled across, and armed with sharp spiny points at its front and edges. We easily take him up, for his means of escape are feeble, as he uncouthly shuffles on his short legs over the sand; and his bellicose instincts are not strongly developed, nor, if they were, have those long levers of arms any formidable powers of offence. Latreille gave to the genus the title of Corystes; which signifies a warrior armed for battle, from κόρυς, a helmet, but its inoffensiveness belies the appellation.[62] Pennant had already conferred on the species the name of Cassivelaunus, the ancient British chief immortalized by Cæsar. If you were to ask me why this obscure crab should bear a name so renowned, I can answer only by conjecture. The carapace is marked by wrinkles, which, while in some specimens they suggest nothing, in others, especially old males, bear the strongest and most ludicrous resemblance to the face of an ancient man. I have taken specimens in which the vraisemblance was so perfect as to strike me, and others to whom I showed it, with amazement. Now Pennant, as is well known, had strong sympathies with his British ancestry; and perhaps, by a not extravagant stretch of imagination, his playful fancy saw the features of the grand old Celtic warrior perpetuated on this Crab, which he first met with, too, be it remembered, on the Welsh coast.
Mr. Couch, in his Cornish Fauna, notices the unusual length of the antennæ. “These organs,” he says, “are of some use beyond their common office of feelers; perhaps, as in some other crustaceans, they assist in the process of excavation; and, when soiled by labour, I have seen the Crab effect their cleaning by alternately bending the joints of their stalks, which stand conveniently angular for this purpose. Each of the long antennæ is thus drawn along the brush that fringes the internal face of the other, until both are cleared of every particle that adhered to them.” This suggested use of the antennæ does not seem to me to be a very felicitous guess of the excellent Cornish naturalist: I should fancy them to be somewhat inefficient instruments in excavation: perhaps I can help him to a better. I have observed that, when these Crabs are kept in an aquarium, they are fond of sitting bolt upright, the antennæ placed close together, and also pointing straight upward from the head. This is, doubtless, the attitude in which the animal sits in its burrow, for the tips of the antennæ may often be seen just projecting from the sand. When the chosen seat has happened to be so close to the glass side of the tank as to bring the antennæ within the range of a pocket lens, I have minutely investigated these organs, without disturbing the old warrior in his meditation. I immediately saw, on each occasion, that a strong current of water was continuously pouring up from the points of the approximate antennæ. Tracing this to its origin, it became evident that it was produced by the rapid vibration of the foot-jaws, drawing in the surrounding water, and pouring it off upwards between the united antennæ, as through a long tube. Then, on examining these organs, I perceived that the form and arrangement of their bristles did indeed constitute each antenna a semi-tube, so that when the pair were brought face to face the tube was complete. It is difficult to make this arrangement intelligible by mere words; but I may say that if either of the antennæ were broken off in the middle and viewed vertically, the bristles would be seen to project from each side of the inner face, in a curved form, each making about a fourth of a circle, so that the two corresponding bristles enclose, with the body of the antenna, a semicircle. Of course, those of the opposite antenna make another semicircle, and, when placed face to face, the points of the bristles just cross each other, and a circle is enclosed. Now, the whole length of the antennæ (about an inch and a half) is closely beset with these bristles, and thus a long row of rings is formed with very narrow interspaces between them; and these rings do in effect constitute a tube quite sufficient to retain the stream of water that is poured through it.
I think then that we may, with an approach to certainty, conclude that the long antennæ are intended to keep a passage open through the sand, from the bottom of the burrow to the superincumbent water, for the purpose of pouring off the waste water, rendered effete by having bathed the gills: and it is one of those exquisite contrivances and appropriations of structure to habit which are so constantly exciting our admiration in the handiwork of the ever blessed God, which cannot be predicated by the à priori reasoner, however astute, but are ever rewarding the research of the patient observer.
Our walk along the sands with steady downcast poring gaze suddenly ends, and we find ourselves among low ledges of black rock (ruddy, however, in its recent fractures, for it is the old red sandstone), clad with sweltering weed, and intersected by little sparkling pools and basins, in which the tiny fishes and entangled prawns shoot hither and thither at our approach. It is the low-lying ridge in the midst of the broad sandy bight that I have already spoken of. Well, n’importe; there is plenty of game to be obtained here, and all is fish that comes to our net. What have we here, creeping over the broad brown leathery leaf of this Laminaria? Is it a little scrap torn from an old newspaper? It looks like it at the first glance, only that it moves steadily onward with a smooth gliding motion, which shows that it possesses a life of its own. Examine it closely: it is exactly like a bit of white paper, about as large as a rose leaf, and cut into that shape, only with an even edge, its clear white surface marked all over with black parallel lines, some thinner, some thicker, running lengthwise, and as clear as if drawn with a pen. What answers to the base of the leaf is the head of the creature, the pointed end being the tail, where the two most strongly marked black lines meet; from the head end arise two curious ear-like leaflets, which are studded with crowded black dots, and are thrown back upon the general surface. With a lens we may discern on the surface of the body, just between these ear-like tentacles, a group of black specks. These are ascertained to be veritable eyes, notwithstanding their number, for they have a cornea, a light-refracting body surrounded with pigment, and a nerve-bulb.
As the animal glides over the surface of the smooth weed, or over the inequalities of the rough rock, we see that its thin papery margin is frequently thrown up into waves, or folds, more or less distinctly revealing the inferior surface. The movement is very even and uniform, but the mode by which it is effected has not been satisfactorily explained. It has been asserted that certain staff-like bristles which project from the skin are used as oars, but this seems doubtful. It is certain that the whole body of the animal, as of the entire class to which it belongs, is densely clothed with minute vibratory cilia; and these, while they probably serve as organs of locomotion in freely swimming, do also without doubt make the whole skin a highly delicate and sensitive organ of touch.
It is asserted of the near allies of this species, and probably is equally true in this case, that if an individual be cut to pieces, every portion continues to live and feel, from whatever part of the body it may be taken; and what is not a little remarkable, each piece, even if it be the end of the tail, as soon as the first moment of pain and irritation has passed, begins to move in the same direction as that in which the entire animal was advancing, as if the body were actuated throughout by the same impulse; and, moreover, every division, even if it is not more than the eighth or tenth part of the creature, will become complete and perfect in all its organs.[63]
You would naturally expect to find the creature’s mouth at the front end, where the two tentacles are placed, and the group of eyes, but you would search for it there in vain. It is, in fact, situated most strangely in the very midst of the belly; that is, at the very centre of the inferior surface. And its structure is not less peculiar than its locality. It consists of an orifice, in the midst of which lies a sort of trumpet of enormous extent when opened, but when not in active use thrown into many folds, which, when the animal wishes to seize prey, are thrust forth, and being partly opened, take the appearance of many irregular tentacles radiating in all directions, at the centre of which is the œsophagus, leading immediately into a much ramified intestine. The name which is given to this elegant and interesting creature is Eurylepta vittata.[64]
But here is another member of the same class of strange creatures. On turning up a large flat stone, we expose to the light of day what might readily be mistaken for a very long thong of black leather, or rather a narrow strip of Indian-rubber, twisted and tied together, and coiled in all possible contortions. If you take hold of it, you find it not so easy to secure it as you expected, for it is excessively lubricous and soft, and withal so extensile and so tough, that you may pull one of the coils to almost any length without lifting the rest of the creature. However, you at last contrive to raise the slippery subject, and commit it safe to your tank at home, in which it will live an indefinite while; often invisible for weeks at a time, lying concealed under some of the stones, then seen perhaps in every corner of your aquarium at once, stretching from one stone to another, and coiling around every groin and projection, folded back upon itself, until in the multitude of convolutions you despair of finding head, tail, or any end at all to the uncouth vermin. You may soon discover the signs of its presence, however, in another way, for its voracity is great, and it is a ferocious foe to the tube-dwelling worms; such as the lovely Sabellæ and Serpulæ, thrusting its serpent-like head into their tubes, and dragging out the hapless tenant to be quickly swallowed.
The animal is named Nemertes Borlasii, or sometimes Borlasia longissima, in allusion to Dr. Borlase, the historian of Cornwall. It is also occasionally termed the Long-worm, par excellence, a name whose appropriateness will appear from the fact that it sometimes reaches a length of thirty feet, with a breadth of an eighth of an inch.
Mr. Kingsley has drawn the portrait of this ciliated worm; and if he has painted it in somewhat dark colours, and manifested more than a common measure of antipathy to it, we must confess that the physical and moral lineaments of the subject do in some degree justify the description. I will quote his vivid words.
“There are animals in which results so strange, fantastic, even seemingly horrible, are produced, that fallen man may be pardoned if he shrinks from them in disgust. That, at least, must be a consequence of our own wrong state; for everything is beautiful and perfect in its place. It may be answered, ‘Yes, in its place; but its place is not yours. You had no business to look at it, and must pay the penalty for intermeddling.’ I doubt that answer: for surely, if man have liberty to do anything, he has liberty to search out freely his Heavenly Father’s works; and yet every one seems to have his antipathic animal, and I know one bred from his childhood to zoology by land and sea, and bold in asserting, and honest in feeling, that all without exception is beautiful, who yet cannot, after handling, and petting, and admiring all day long every uncouth and venomous beast, avoid a paroxysm of horror at the sight of the common house-spider. At all events, whether we were intruding or not, in turning this stone, we must pay a fine for having done so; for there lies an animal, as foul and monstrous to the eye as ‘hydra, gorgon, or chimera dire,’ and yet so wondrously fitted for its work, that we must needs endure for our own instruction to handle and look at it. Its name I know not (though it lurks here under every stone), and should be glad to know. It seems some very ‘low’ Ascarid or Planarian worm. You see it? That black, slimy, knotted lump among the gravel, small enough to be taken up in a dessert-spoon. Look now, as it is raised and its coils drawn out. Three feet! Six—nine at least, with a capability of seemingly endless expansion; a slimy tape of living caoutchouc, some eighth of an inch in diameter, a dark chocolate-black, with paler longitudinal lines. Is it alive? It hangs helpless and motionless, a mere velvet string across the hand. Ask the neighbouring Annelids and the fry of the rock fishes, or put it into a vase at home, and see. It lies motionless, trailing itself among the gravel; you cannot tell where it begins or ends; it may be a strip of dead sea-weed, Himanthalia lorea, perhaps, or Chorda filum; or even a tarred string. So thinks the little fish who plays over and over it, till he touches at last what is too surely a head. In an instant a bell-shaped sucker mouth has fastened to its side. In another instant, from one lip, a concave double proboscis, just like a tapir’s (another instance of the repetition of forms), has clasped him like a finger, and now begins the struggle; but in vain. He is being ‘played’ with such a fishing-rod as the skill of a Wilson or a Stoddart never could invent; a living line, with elasticity beyond that of the most delicate fly-rod, which follows every lunge, shortening and lengthening, slipping and twining round every piece of gravel and stem of sea-weed, with a tiring drag such as no Highland wrist or step could ever bring to bear on salmon or trout. The victim is tired now; and slowly, yet dexterously, his blind assailent is feeling and shifting along his side, till he reaches one end of him; and then the black lips expand, and slowly and surely the curved finger begins packing him end foremost down into the gullet, where he sinks, inch by inch, till the swelling which marks his place is lost among the coils, and he is probably macerated into a pulp long before he has reached the opposite extremity of his cave of doom. Once safe down, the black murderer contracts again into a knotted heap, and lies like a boa with a stag inside him, motionless and blest.”[65]
VI.
JUNE.
We are on the narrow shingle-beach of Maidencombe, or, sometimes, more familiarly, Minnicombe; one of the slight indentations of this line of coast, which, from the mouth of the Exe to Start Point, runs nearly north and south, and so looks right up-channel, and receives the full violence of the keen and blustering east winds.
Away down the gentle slope till we come to the line where the wavelets are kissing the rock, where the next step would put us into King Canute’s circumstances, where the sea is washing to and fro the shaggy weed, and just preventing it from assuming the shrivelled and blackened condition, into which the tufts a little above are fast falling under the baking powers of this June sun; and here, on these very weeds, now submerged, now dry, are crawling some uncouth beings of a dark liver colour or purple-brown hue. The creature passes by the name of Sea-hare;[66] a not inappropriate designation, for I have often seen it in postures when the resemblance to a couching hare was spontaneously suggested. Around Weymouth, where it is common, the fishermen and shore-boys call it the Sea-cow; which is not a bad hit, though not so happy as that of hare. In each case, the feature which strikes the imagination and suggests the comparison with the quadruped, is the pair of tentacles which stand erect, but a little diverging, from the back of the head, and which consist of an expanded lamina infolded at the base, and, as it were, cut off slantingly, so as to look like a hare’s ears. There are, indeed, two pairs of tentacles of similar structure; but the front pair are more commonly stretched forward horizontally, and held near the ground, so as to be much less conspicuous.
The animal is one of the Sea-slugs, allied, not remotely, to the Doris and the lovely Eolis, which occupied our attention some time ago. The order to which it belongs is, however, distinguished from them by having the breathing organs covered. In our Sea-hare these take the form of complicated leaflets, which are placed upon the middle of the back, and are protected by a broad plate of shell, somewhat like a watch-glass of irregular outline, very thin and transparent, and very brittle when dry. During life, this shelly plate is imbedded in the substance of the skin of the back, a thin layer of which clothes it; so thin that it can be very readily seen and felt notwithstanding. The mantle is much developed, forming two great irregular wing-like lobes, which stand up on each side of the body, and at pleasure either arch over the gill-shield, or are depressed, and widely expose it. It is reported that these mantle-lobes are capable of being used as swimming-fins, by their undulations; but I doubt the correctness of the observation.
When full-grown, our Sea-hare is three inches in length, and upwards of an inch high. Its body is of a slimy, fleshy, slug-like texture, varying much in colour; sometimes being dark olive-green, sometimes red-brown, sometimes deep purple, occasionally clouded with blue: sometimes the hue is uniform; at others, it is varied by light dots, or handsomely marked with dark rings enclosing white areas. Its figure is extremely versatile; so that, when crawling, it scarcely exhibits the same outline for two minutes together.
See what has happened. On dropping one of the slimy beasts into this phial of clear sea-water, it immediately resented the incarceration by beginning to pour out from beneath the lobes of the mantle a thin stream of fluid of the most royal purple hue, which freely diffused itself through the water. And see! it is still copiously exuding; and the whole contents of the bottle are now fast becoming of so fine and rich a tinge, as already to veil the form of the animal. Attempts have been made to employ this secretion in the arts; but the hue is fleeting. According to Cuvier, it assumes in drying the beautiful deep hue of the flower known as the sweet scabious, and remains long unaltered by exposure to the air. The purple tint is readily transferred to spirit, when the animal is immersed in it; the tincture retains the colour for a while, but ultimately becomes of a deep clear port-wine tint. Linen, dyed with the fluid, soon fades to a dingy brown.
It is a curious coincidence that this mollusk possesses a more recondite analogy with herbivorous mammalia, than a fleeting resemblance of form. Professor Grant has shown that it has three stomachs, like the ruminants. First, a short narrow gullet dilates into a large membranous crop; a curved bag, which is generally filled with pieces of coarse sea-weed. This large crop or paunch occupies the right side of the body, and opens laterally into the middle stomach, which is the smallest of all, and performs the part of the gizzard. Its coats are thickened; and the interior callous lining is besat with firm horny processes, in the form of rhomboidal plates or molar teeth, which serve to compress the softened vegetable matter transmitted in small portions from the first stomach. The third cavity of this complex apparatus is placed on the left side of the body; its interior surface is studded with sharp, horny spines, resembling canine teeth, to pierce and subdivide the coarse food, and thus prepare it for the action of the gastric juice and other fluids accessory to digestion, which enter the stomach from adjacent organs.[67]
The complexity of this structure has reference to the coarseness of the materials on which the animal subsists; the leathery fronds of the olive sea-weeds, which slowly and with difficulty yield their nutritive elements to the digestive functions.
This great, flabby Sea-Slug has a mythic history full of wild romance. Our species has been often called depilans, because the fluid which exudes from it was said to have the power of causing the hair to fall from the human head which it touched; and the common species of Southern Europe retains the appellation in the records of science. The Mediterranean fishermen have so great a horror of it that no bribes will induce them to handle it willingly; and they tell strange stories of wounds being produced, limbs being mortified, and even death itself being caused, by accidental or foolhardy contact with the potent creature.
Bohadsch has given, on the authority of personal observation, a minutely circumstantial account, which it seems a hyper-scepticism to doubt. When removed from the sea, and placed in a vessel, there exuded a large quantity of a limpid and somewhat mucilaginous fluid, exhaling a sweetish, sickening, peculiar smell: but besides this, and distinct from its purple secretion, the Aplysia excreted also a milky liquor, formed in an internal conglobate gland, which seems to be analogous to the kidney of vertebrate animals. As often as he took the Aplysia from the vase of sea-water and placed it on a plate with the view of more narrowly examining its structure, the room was filled with a nauseous odour, compelling his wife and brother to leave the room, lest sickness and vomiting should follow. He himself could scarcely endure it, and during the examination had repeatedly to go out and breathe a purer air. His hands and cheeks swelled after handling the creature for any length of time, and as often as it ejaculated its milky secretion; but he is uncertain whether the swelling of the face proceeded from the halitus merely, or from his having accidentally touched it with the hand besmeared with the liquid: probably the latter was the real cause, for when he purposely applied some of it to his chin, some hairs fell from the part.[68]
We may add to this account, as being in a measure confirmatory of its probability, the statement of a perfectly dependable naturalist, Mr. Charles Darwin, that he found a species of Aplysia at St. Jago, one of the Cape Verd Isles, from which “an acrid secretion, which is spread over its body, causes a sharp stinging sensation, similar to that produced by the Physalia,[69] or Portuguese man-of-war.”[70] And yet I have myself freely handled Aplysiæ in health and vigour, both here and on the coast of Jamaica, without perceiving the slightest unpleasant sensation.
But in the days of ancient Rome the poor Sea-hare had a far more terrific reputation. In those dark days of the Empire when no one’s life was secure against insidious assassination, and when professed poisoners were at the command of such as could afford to pay their hire, this mollusk was an essential element of the fatal draught. “Locusta used it to destroy such as were inimical to Nero; it entered into the potion which she prepared for the tyrant himself; and Domitian was accused of having given it to his brother Titus. To search after the Sea-hare was to render one’s-self suspected; and when Apuleius was accused of magic, because, forsooth, he had induced a rich widow to marry him, the principal proof against him was that he had hired the fishermen to procure him this fearful animal.”[71] He succeeded, however, in showing, to the satisfaction of his judges, that his object was merely the gratification of laudable scientific curiosity.
Peering into the deep and narrow fissures with which the rocky ledge is cleft, we observe some shells which properly belong to the deep sea bottom, but have been doubtless washed into the shallow, by some heavy ground-swell, and left where we now see them. Here are several fragments, and one or two nearly perfect specimens, of what looks like an elephant’s tusk in miniature, but is really the shell of a small Gastropod mollusk commonly known as the Tusk-shell.[72] In colour, form, and curvature, the resemblance is complete, but the length of a perfect shell rarely exceeds an inch and a half, with a diameter of one-eighth of an inch at the larger end. The animal is remarkable for having long been a subject of dispute with learned zoologists as to its true affinities; by some being considered as a true mollusk allied to the Limpets, by others as a worm allied to the Serpulæ. Anatomy determines it to be rightly located by the former opinion, and yet the possession of red blood, and some other peculiarities belonging to the Annelida, indicate a curious relationship with this class, so that we may consider it as one of those interesting forms which link together two great divisions of the animal kingdom.
When the Tusk-shell is found alive, we rarely can see more of the soft parts than a sort of white cushion occupying the mouth of the shell, and occasionally protruding or receding, with a little conical point projecting from the centre of it. You might keep it for weeks, as I have done, and see no more, by the most assiduous watching, than this; but at some fortunate moment you might perchance see the whole foot, of which this little cone is the extremity, thrust far out of the cushion-like collar, when you would discern a wide lobed membrane, fringing the base of the foot, trumpet-like in shape, or resembling the blossom of a convolvulus, with the thick and pointed foot projecting from its centre like a pistil.
These sluggish white mollusks ordinarily live on the muddy sea-floor, or burrow in it, where they devour minuter animals, such as Foraminifera, and the spawn and larval forms of their fellow Mollusca. They are rarely taken alive at a less depth than ten fathoms.
But we have also an example of a much rarer shell, the Torbay Bonnet, or Cap of Liberty.[73] The shape, which is exactly that of the ancient Phrygian bonnet, or the modern emblem of liberty, is sufficiently commemorated in all the appellations by which it is known, both scientific and popular. This specimen is but an empty shell, but the freshness of the colours, and the beautiful polish of the interior show that the animal cannot have been long dead, for the porcellaneous smoothness and gloss of shells very soon become defaced after their exposure by the death and decay of the soft parts. The interior of this shell is of a most lovely rose-pink, very glossy, and the exterior is nearly of the same hue, though this is concealed by a horny skin which closely invests it, and is covered with a shaggy pile that projects even beyond the edge, in the form of a ragged yellow fringe. This rough epidermis is of a hue varying from a bright yellow-olive to a dull wood-brown; it is frequently rubbed off in the upper parts, when the natural hue of the shell is there seen.
This species is rare enough, and large enough, and handsome enough to be a prize worth finding, when picked up in so fresh a condition as this; but, of course, it is more valuable when it occurs in a living state. But this scarcely ever happens except by dredging, or by trawling. I have frequently had it brought to me by trawlers both at Weymouth and Tenby, oftenest by the former, who get it in deep water, from thirty to fifty fathoms, on the western side of Portland.
The living animal is not unworthy of its elegantly painted house. Its colour is usually pale yellow, with a rose-pink mantle, bordered by a fine orange-coloured fringe. The head is large and swollen, furnished with tentacles, which carry the eyes at their bases. The tongue-ribbon carries seven rows of teeth, of which the central one differs in shape from the rest.
I have kept a specimen in the aquarium for a considerable time, with very little addition to my knowledge as the result. It remained adhering to the scallop shell on which it was found almost all the time I had it, occasionally shifting a hair’s-breadth to the one side or the other. Almost always the fringed edge of the shell was so closely applied to the support as absolutely to forbid intrusion; but now and then a very slight lifting of the edge all round gave me the narrowest possible peep at the broad cream-coloured foot adhering to its rest. Thus it went on tantalizing me, till after some months I lost it, I forget how.
A close ally of this form is a pretty shell which we often obtain by dredging, called the Cup-and-Saucer Limpet. It is a pretty little white porcellaneous cone, with a curved plate of thin shell projecting from the side of the interior, like a semi-cup within the cup. It is named Calyptræa. Both this and the Torbay Bonnet have been ascertained to manifest domestic instincts, in sitting on their eggs till they are hatched. According to MM. Audouin and Milne Edwards, the parent Calyptræa “disposes them under her belly, and preserves them, as it were imprisoned, between the foot and the foreign body to which she adheres, her patelloid shell thus serving not only to cover and protect herself, but as a shield to her offspring. These eggs are oval bodies of a yellow colour, enclosed in membranous capsules, which are elliptical, flattened, translucid, and filled with an albuminous matter. The number of these little capsules varies from six to ten; they are connected among themselves by a footstalk, so as to represent a sort of rosette; each of them contains from eight to ten eggs. It appears that the young Calyptræa are developed under this sort of maternal roof, and do not quit it until they are in a condition to affix themselves, and are provided with a shell sufficiently hard to protect their own bodies.”[74]