The most famous of botanists compiled a floral almanac; the months, and in some cases the weeks, being associated with the development and flowering of significant plants. So might it be possible to ascribe to particular months the tokens with which the obliging sea bestrews the beaches. It is not proposed herein to attempt any such design, which would involve special knowledge of the science of conchology and the compilation of the records of years of patient observation. A few examples of the material on which the delightful work might be undertaken are given, so that the wealth of one brief strip of beach may be taken as typical of a vast stretch of calm waters within the Great Barrier Reef.
The ridges and furrows of the cyclone season, when the clean sand is covered and stained with weed, dead and living molluscs, coral, leaves carried from the hills by flooded streams, all fermenting in the heat, tell that Christmas is past and March not yet over. Many a year passes without such a storm as compels the groaning ocean to ravage its reefs. Then the beaches, during the first three months are not particularly fertile, nor are the shells to be found special or peculiar. In April many specimens of the mollusc known as Tapes, of which there are several species, are cast ashore, empty but fresh. In life the animal buries itself in the mud at the edge of the sand, and some disturbance of natural conditions, possibly due to the fresh water from flooded rivers, causes seasonal mortality. The most conspicuous of the species is that known as “literati,” because of the erratic scribblings decorating its valves. With others of the genera, it is to be found cast away at other times of the year, but the end of the wet season seems exceptionally direful.
April is confirmed, too, but transiently, by the presence of a frail mollusc (HAMINAEA CYMBALUM) which is washed ashore attached to seaweed, soon to disappear desiccated by the sun and ground to powder. The shell is semi-transparent with a sandy tint, and in form not unlike that of a common snail. As the weather becomes cooler, a thin, delicate bivalve decorates high-water mark. It is one of the tellinas—semi-transparent, lustrous, and fragile—which occurs in muddy sand, but why the species should be more susceptible to the ills of life during a particular season is not apparent. When the fates do conspire against its welfare dozen of bright specimens may be picked up during a casual stroll, the animal having disappeared. The epidemic the beach thus announced with pink and glittering shells coincides with low night tides, which possibly leave the inefficiently protected animals exposed to the attacks of uncustomary enemies which thrive only when the muddy banks are exposed. The cause of the exhibition of the relics is not of so much concern to the unlearned observer as the relics themselves and the part they play in signifying the progress of the season. If strong winds occur during the cool months, among the wreaths of broken seaweed thrown on the beach may be found unbroken and fresh specimens of a singularly beautiful and fragile univalve known commonly and most appropriately as the “bubble shell” (HYDATINA PHYSIS), which when alive is a most lovely object, its fine spiral lines being black and faint yellow with faint purple edges, while the mantle is fringed with light blue intermingled with pale yellow. In some specimens the base colouring is fawn, the lines, of varying width, being brown and “comely crinkled,” like the face of the pleasant old woman of whom a poet wrote. Such a frail shell is subject to many mischances before it reaches the beach, and a few hours of exposure to the sun tarnishes its lustre. To obtain it in perfection the beach must be patrolled every day during due season, and very rarely is the collector rewarded by the discovery of unsullied specimens.
When the chill is out of the surface the spring-time of the sea begins. Vegetable life is strenuous, so that one may chance to see a lazy turtle bearing on its back a weedy garden. The water is alive. Miles of space are belted with that plant to which Captain Cook applied a significant name, likening it in its myriads to “sea sawdust.” Some dare call it “whale spawn,” forgetful that the whale is not a fish. Others assert it to be none other than the “coral insect,” which does not exist save in the minds of those who write odes to such creatures:
“Ye build, ye build, but ye enter not in,
Like the tribes whom the desert devoured in their sin.”
It consists of minute vegetation in bundles, to be individualised under a strong microscope, though when countless billions drift on to the beaches and die and become green and grey with corruption, the fumes are by no means in proportion to the marvellous littleness of the individual plants. Then we know by the organs of scent and sight that August has come. The beaches are foul. The breakers roll in unbroken or with a muddy, froth, for the scum acts as oil, calming even troubled water.
The Red Sea is said by some authorities to derive its title from the scum formed by this plant (TRICHODESMIUM ERYTHRAEUM), which is strongly impregnated with iodine. It emits a most disagreeable odour and exhales a gas which affects the mucous membrane, causing in some individuals sneezing and inflammation of the eyes. One amateur fisherman of considerable experience and by no means susceptible to intangible irritations, and not to be diverted from his sport by trifles, has frequently been compelled to move from a favourite ground by a stream of the scum drifting to his anchored boat. The fumes gave intense smartness to the eyes, which were relieved by a gush of tears, but keen discomfort recurred when the tears were wiped away.
Following the least desirable of marine phenomena is that which is known as the “blanket weed,” which floats ashore in loathsome blobs, a hand's breadth and more, the centre a grey, solidified slime, with a periphery of long, dull green, slimy, shapeless fringes Individual plants coalesce on the sand and, mingling with other weeds, cover respectable beaches with a woolly, compact mass not unlike a rough, thick blanket, but teeming with unpleasantnesses. Isolated plants cling to ropes, which become garlanded with thickened slime, from which evil-smelling mud oozes. Offensive to man afloat and ashore, the “blanket weed” is a luxury to mullet and garfish, for during its period both may be seen in shoals skimming the surface of the sea in abandonment of habitual shyness, and the stomachs of both are found to be full of the greenish-grey slime. With the compliance of the sun the impurity disappears, giving place to the graceful weed of vivid green that attaches itself to dead and whitened shells and fingers of coral covered at low water. Every flood-tide deposits a zone of shells splashed with green, while the shallows glow as a field of rich pasturage. In favourable situations, such as the upper part of a long immersed log, coated to the water-line with goose barnacles, the plant grows long and luxuriantly, falling on each side like a silken mantle.
One other season, ephemeral but universal, do the babbling but truth-telling beaches record. No rocky cove, no smooth strand, no rubbish-accumulating creek, no mangrove-fringed islet, no coral esplanade white under the tropic sun, no sand-bank with crest of windshaken bush, is free. It is Christmas. Christian and pagan alike tell it to the sea, and the sea tells it to the beaches in—corks.
Though there are grounds for the belief that some molluscs are seasonal in their appearances and disappearances, the majority are always with us, though subject to many casualties. A few months since an epidemic broke out among a certain species of sea urchins (Echinus), spherical animals with shells thickly set with spines, keen and exceedingly brittle. The beaches were strewn with thousands of the dead, no apparent exterior injury having been suffered. The particular species afflicted gathers to itself, seemingly as a disguise, but perhaps as ballast, the dead shells of cockles, which are retained by the spines. It was noticed that the dead were not encumbered.