My Tropic Isle - Edmund James Banfield (little bear else holmelund minarik .txt) 📗

The sponge embraces the slender mollusc so maternally that rude yawning is forbidden. It may lisp only and in smooth phrases, such as "prunes" and "prisms"; and, moreover, the host further insures it against molestation by the diffusion of an exceptionally powerful odour, which, though to my sense of smell resembles phosphorus, is, I am informed on indubitable authority, derivable from the active form of oxygen known as ozone. Experimentally I have placed these molluscs in fresh water, to find it quickly dyed to a rich amber colour while acquiring quite remarkable pungency. Even after the third change the water was impregnated.

Interest in the mollusc became secondary upon the discovery of the host and in consideration of the part it plays in the production of one of the special effects of coral reefs; but the mollusc serves another and timely purpose--purely personal and yet not to be disregarded. It indicates a dilemma with which the wilful amateur in the first-hand study of conchology is confronted. Although, as I have said, no local knowledge of identity was available, reference to a well-disposed expert secured the information that its title in science is VULSELLA LINGULATA; that some twenty species are known; that they all associate with sponges, and that possibly different species inhabit different kinds of sponges. It may seem unpardonably gratuitous on the part of one professedly ignorant to offer general observations upon natural phenomena; but as I find myself among the great majority who do not know and who may be more or less interested and anxious to learn, I claim justification in describing that which to me is novel and rare. In this splendid isolation I cannot hope to illuminate primary investigations with the searching light in which science basks unblinkingly, for the nearest library of text-books is close on a thousand miles away. Nor can I keep all my observations to myself. There are some which, like murder, "will out," conscious though I am of meriting the censure of the learned.

With this off my mind, let me return to the tenement sponges, which may be likened to so many independent and flourishing manufactories of ozone. Apart from the odour of brine common to every ocean and the scents of the algae and some of the flowering plants of the sea, which are similar all over the world, a coral reef has a strong and specific effluence. The skeletonless coral (ALCYONARIA) has a sulphurous savour of its own, and the echini and beche-de-mer are also to be separately distinguished by their fumes. Anemones, great and small, seem to disperse a recognisable scent as from a mild and watery solution of fish and phosphorus. But of all the occupants of the reef none are so powerful or so characteristic in this respect as sponges. Puissant and aggressive, these exhalations are at times so strong as to almost make the eyes water, while exciting vivid reminiscences of old-fashioned matches and chemical experiments. Substantial, wholesome, and clean--though generated by a wet, helpless creature having no personal charms, and which, having passed the phase of life in which it enjoyed the gift of locomotion, has become a plant-like fixture to one spot--the gas mingles with other diffusions of the reef, recalling villanous salt-petre and sheepdips and brimstone and treacle to the stimulation of the mental faculties generally.

Invariably an afternoon's exploration of the coral reef is followed by a drowsy evening and a night of exceptionally sweet repose. No ill dreams molest the soothing hours during which the nervous system is burnished and lubricated, and you wake refreshed and invigorated beyond measure. I have endeavoured to account for the undoubted physical replenishment and mental exhilaration largely from the breathing of air saturated with emanations from the coral and sea things generally.

In the course of three hours' parade and splashing in the tepid water, ever so many varieties of gas more or less pungent and vitalising--gas which seems to search and strengthen the mechanism of the lungs with chemically enriched air, to tonic the whole system, and to brighten the perceptive faculties, have been imbibed. Exercise and the eagerness with which wonders are sought out and admired may account in part for present elation and balmy succeeding sleep, but the vital functions seem, if my own sensations are typical, to receive also a general toning up. Twice a month at least a man should spend an afternoon on a coral reef for the betterment of body and brain. On the face of it this is counsel of perfection. Only to the happy few is such agreeable and blest physic proffered gratis. Yet the whole world might be brighter and better if coral reefs were more generously distributed. Breathing such subtle and sturdy air, men would live longer; while the extravagant life of the reef, appealing to him in fine colours and strange shapes, would avert his thoughts from paltry and mean amusements and over-exciting pleasures. The pomp of the world he would find personated by coral polyps; its vanities by coy and painted fish; its artfulness represented by crabs that think and plan; its scavenging performed by aureoled worms.

Although students of conchology are familiar with several species of LIMA, I am eager to include it in these haphazard references, because my first acquaintance with a living specimen afforded yet another experience of the versatility of the designs of Nature. It is truly one of the "strange fellows" which Nature in her time has framed. Living obscurely in cavities, under stones, inoffensive and humble, the Lima enjoys the distinction of being, the permanent exemplification of the misfit, its body being several sizes too large as well as too robust for its fragile, shelly covering. The valves are obtusely oblong, while the animal is almost a flattened oval, the mantle being fringed with numerous bright pink tentacles, almost electrical in their sensitiveness.

Though anything but rotund, so full in habit (comparatively speaking) is the body of the lima that the valves cannot compress it. Except at the hinges they are for ever divorced, an unfair proportion of the bulging body being exposed naked to the inclemency and hostility of the world. "All too full in the bud" for those frail unpuritanical stays, the animal seems to be at a palpable disadvantage in the battle of life, yet the lima is equipped with special apparatus for the maintenance of its right to live. By the expansion and partial closing of the valves it swims or is propelled with a curiously energetic, fussy, mechanical action, while the ever-active pink rays--a living, nimbus--beat rhythmically, imperiously waving intruders off the track.

The appearance and activities of the creature are such as to establish the delusion that it is not altogether amicable in its attitude towards even such a bumptious and authoritative product of Nature as man. Its agitated demonstrations--whatever their vital purpose may be--to the superficial observer are danger signals, a means of self-preservation, as a substitute for the hard calcareous armour bestowed upon other molluscs. The fussy red rays may impose upon enemies a sense of discretion which constrains them to avoid the lima, which, though hostile in appearance, is one of the mildest of creatures. The tentacles, too, have a certain sort of independence, for they occasionally separate themselves from the animal upon the touch of man, adhering to the fingers, while maintaining harmonic action, just as the tip of a lizard's tail wriggles and squirms after severance.

Most of the blocks of submerged, denuded coral are the homes of certain species of burrowing molluscs, the most notable of which are the "date mussels" (LITHOPHAGA). The adult of that designated L. TERES is over two inches long and half an inch in diameter; glossy black, with the surface delicately sculptured in wavy lines; the interior nacreous, with a bluish tinge. This excavates a perfectly cylindrical tunnel, upon the sides of which are exposed the stellar structure of the coral. A closely related species (STRAMINEA), slightly longer, and generally of smooth exterior, partially coated with plaster, muddy grey in colour, adds to the comfort and security of existence by lining its tunnel with a smooth material, a distinction which cannot fail to impress the observer. In each case the mollusc is a loose fit in its burrow, having ample room for rotation, but the aperture of the latter is what is known as a cassinian oval, and generally projects slightly above the surface of the coral.

The animal is a voluntary life prisoner, for the aperture has the least dimension of the tunnel. The genus is known to be self luminous--a decided advantage in so dark and narrow an habitation. It seems to me to be worthy of special note that an animal enclosed by Nature in tightly fitting valves should also be endowed with the power of mixing plaster or secreting the enamel with which its tunnel is lined and of depositing it with like regularity and, smoothness to that exhibited in its more personal covering which grows with its growth. The mollusc in its burrow in the depths of a block of coral, white as marble, with its own light and its self-constructed independent wall, appeals to my mind as evidence of the care of Nature for the preservation of types, while from such retiring yet virile creatures man learns earth-shifting lessons. A quotation from Lyell's "Principles of Geology" says that the perforations of Lithophagi in limestone cliffs and in the three upright columns of the Temple of Jupiter Serapis at Puzzuoli afford conclusive evidence of changes in the level of sea-coasts in modern times--the borings of the mollusc prove that the pillars of the temple must have been depressed to a corresponding depth in the sea, and to have been raised up again without losing their perpendicularity.

The date-mussels play an important part in the conversion of sea-contained minerals into dry land. Massive blocks of lime secreted by coral polyps being weakened by the tunnels of the mussels are the more easily broken by wave force; and being reduced finally to mud, the lime, in association with sand and other constituents, forms solid rock.

A feature of another of the coral rock disintegrating agents is its extreme weakness. It is a rotund mollusc with frail white valves, closely fitting the cavity in which it lives. As it cannot revolve, the excavation of the cavity is, possibly, effected by persistent but necessarily extremely slight "play" of the valves; but the animal appears to be quite content in its cramped cell with a tiny circular aperture (generally so obscured as to be invisible), through which it accepts the doles of the teeming, incessant sea.


CHAPTER XV



BARRIER REEF CRABS

"Reasoning, oft admire
How Nature, wise and frugal, could commit
Such dispositions with superfluous hand."

MILTON.


So much of the time of the Beachcomber is spent sweeping with hopeful eyes the breadths of the empty sea, policing the uproarious beaches, overhauling the hordes of roguish reefs, and the medley concealed in cosy caves by waves that storm at the bare mention of the rights of private property, that he cannot avoid casual acquaintance with the scores of animated things which ceaselessly woo him from the pursuit of his calling. Should he be inclined to ignore the boldly obvious distractions from serious affairs, there are others, not readily discernible, which have singularly direct and successful methods of fixing attention upon themselves.

Roseate or sombre your humour as you patrol the reefs, it is liable to be changed in a flash into clashing tints by inadvertent contact with a warty ghoul of a sea-urchin, a single one of whose agonising spines never fails to bring you face to face with one of the vividest realities of life. A slim but shapely mollusc known as Terebellum or augur,