The conveyance of sound through the inelastic medium of water is so difficult that it has been called the world of silence. This is only comparatively true. The fish has an auditory cavity, which, though simple in itself, certifies the ordinary conviction of sound, but it is dull and imperfect; and perhaps all marine creatures have other means of communication. There is an instance, however, of musical sounds produced by marine animals, which seems to show an appreciation of harmony. In one of the lakes of Ceylon, Sir Emerson Tennent heard soft musical sounds, like the first faint notes of the aeolian harp or the faint vibrations of a wineglass when its rim is rubbed by a wet finger. This curious harmony is supposed to be produced by a species of testaceous mollusk. A similar intonation is heard at times along the Florida coast.
Interesting as this may be, as indicating an appreciation of that systematic order in arrangement which in music is harmony, it does not alter the fact that to the ears of the diver, save the cascade of the air through the life-hose, it is a sea of silence. No shout or spoken word reaches him. Even a cannon-shot comes to him dull and muffled, or if distant it is unheard. But a sharp, quick sound, that appears to break the air, like ice, into sharp radii, can be heard, especially if struck against anything on the water. The sound of driving a nail on the ship above, for example, or a sharp tap on the diving-bell below, is distinctly and reciprocally audible. Conversation below the surface by ordinary methods is out of the question, but it can be sustained by placing the metal helmets of the interlocutors together, thus providing a medium of conveyance.
The effort to clothe with intelligence subaqueous life must have been greatly strengthened among primitive nations by the musical sounds to which I have referred. Those mysterious breathings were associated with a human will, and gave forebodings from their very sweetness. Everywhere they are associated with a passionate or pathetic mystery, and the widely-spread area over which their island home is portrayed as existing strengthens the conclusion that the strange music of the sea belongs not to Ceylon or Florida or the Mediterranean alone. It affords us another instance, by that common enjoyment of sweet sounds, of the chain of sympathy between all intelligent creatures, and better prepares us for familiar acquaintance with the beings which people the sea. We have prejudices and preconceived ideas to get rid of, whose strength has crystallized into aphorisms. "Cold as a fish" and "fish-eyed" are ordinary expressions. Then the touch of a fish, cold, slippery, serpent-like, causes an involuntary shrinking.
But the submarine diver has a new revelation of piscine character and beauty, and perhaps can better understand the enticings of a siren or fantastic Lurlei than the classical scholar. In the flush of aureal light tinging their pearly glimmering armor are the radiant, graceful, frolicsome inhabitants of the sea. The glutinous or oily exudation that covers them is a brilliant varnish. Their lustrous colors, variety of crystalline tints and beautiful markings and spots, attract the eye of the artist even in the fish-market; but when glowing with full life, lively, nimble, playful, surely the most graceful living creatures of earth, air or sea, the soul must be blind indeed that can look upon them unmoved.
The dull optic seen glazing in the death-throes upon the market-stall, with coarse vulgar surroundings, becomes, in its native element, full of intelligence and light. In even the smaller fry the round orb glitters like a diamond star. One cannot see the fish without seeing its eye. It is positive, persistent, prevalent, the whole animate existence expressed in it. As far as the fish can be seen its eye is visible. The glimmer of scales, the grace of perfect motion, the rare golden pavilion with its jeweled floor and heavy violet curtains, complete a scene whose harmony of color, radiance and animal life is perfect. The minnow and sun-perch are the pages of the tourney on the cloth of gold. There is a fearless familiarity in these playful little things, a social, frank intimacy with their novel visitor, that astonishes while it pleases. They crowd about him, curiously touch him, and regard all his movements with a frank, lively interest. Nor are the larger fish shy. The sheeps-head, red and black groper, sea-trout and other, familiar fish of the sportsman, receive him with frank bonhommie or fearless curiosity. In their large round beautiful eyes the diver reads evidence of intelligence and curious wonder that sometimes startles him with its entirely human expression. There is a look of interest mixed with curiosity, leading to the irresistible conclusion of a kindred nature. No faithful hound or pet doe could express a franker interest in its eyes. Curiosity, which I take to be expressly destructive of the now-exploded theory of instinct, is expressed not only by the eye, but by the movements. As in man there is an eager passion to handle that which is novel, so these curious denizens of the sea are persistent in their efforts to touch the diver. An instance of this occurred, attended with disagreeable results to one of the parties, and that not the fish. The Eve of this investigation was a large catfish. These fish are the true rovers of the water. They have a large round black eye, full of intelligence and fire: their warlike spines and gaff-topsails give them the true buccaneer build. One of these, while the diver was engaged, incited by its fearless curiosity, slipped up and touched him with its cold nose. The man involuntarily threw back his hand, and the soft palm striking the sharp gaff, it was driven into the flesh. There was an instant's struggle before the fish wrenched itself loose from the bleeding member, and then it only swung off a little, staring with its bold black eyes at the intruder, as if it wished to stay for further question. It is hard to translate the expression of that look of curious wonder and surprise without appearing to exaggerate, but the impression produced was that if the fish did not speak to him, it was from no lack of intelligent emotions to be expressed in language.
A prolonged stay in one place gave a diver an opportunity to test this intelligence further, and to observe the trustful familiarity of this variety of marine life. He was continually surrounded at his work by a school of gropers, averaging a foot in length. An accident having identified one of them, he observed it was a daily visitor. After the first curiosity the gropers apparently settled into the belief that the novel monster was harmless and clumsy, but useful in assisting them to their food. The species feed on Crustacea and marine worms, which shelter under rocks, mosses and sunken objects at the sea-bottom. In raising anything out of the ooze a dozen of these fish would thrust their heads into the hollow for their food before the diver's hand was removed. They would follow him about, eyeing his motions, dashing in advance or around in sport, and evidently with a liking for their new-found friend. Pleased with such an unexpected familiarity, the man would bring them food and feed them from his hand, as one feeds a flock of chickens. The resemblance, in their familiarity and some of their ways, to poultry was, in fact, very striking. As a little chick will sometimes seize a large crumb and scurry off, followed by the flock, so a fish would sometimes snatch a morsel and fly, followed by the school. If he dropped it or stopped to enjoy his bonne bouche, his mates would be upon him. Sometimes two would get the same morsel, and there would be a trial of strength, accompanied with much flash and glitter of shining scales. But no matter how called off, their interest and curiosity remained with the diver. They would return, pushing their noses about him, caressingly in appearance if not intent, and bob into the treasures of worm and shell-fish his labor exposed. He became convinced that they were sportive, indulging in dash and play for the fun of it, rather than for any grosser object to be attained.
This curious intimacy was continued for weeks: the fish, unless driven away by some rover of prey of their kind, were in regular attendance during his hours of work. Perhaps the solitude and silence of that curious submarine world strengthened the impression of recognition and intimacy, but by every criterion we usually accept in terrestrial creation these little creatures had an interest and a friendly feeling for one who furnished them food, and who was always careful to avoid injuring them or giving them any unnecessary alarm. He could not, of course, take up a fish in his hand, any more than a chicken will submit to handling; but as to the comparative tameness of the two, the fish is more approachable than the chicken. That they knew and expected the diver at the usual hour was a conclusion impossible to deny, as also that they grew into familiarity with him, and were actuated by an intelligent recognition of his service to them. It would be hard to convince this gentleman that a school of fish cannot be as readily and completely tamed as a flock of chickens.
Why not? The fear of man is no instinctive feeling in the invertebrate creation. The pioneer who penetrates into the uninhabited wilds of our Western frontier finds bird and beast fearless and familiar. Man's cruelty is a lesson of experience. The timid and fearful of the lower creation belong to creatures of prey. The shark, for example, is as cowardly as the wolf.
I thought to speak of other marine creations with which the diver grows acquainted, finding in them only a repetition of the same degree of life he has seen in the upper world. But let it be enough to state the conclusion—as yet only an impression, and perhaps never to be more—that in marine existence there is to be found the counterpart always of some animate existence on earth, invertebrate or radiate, in corresponding animals or insects, between whose habits and modes of existence strong analogies are found. The shrimps that hang in clusters on your hand under the water are but winged insects of the air in another frame that have annoyed you on the land.
Let me dismiss the subject with the brief account of a diver caught in a trap.