W. Bede Christie

“ Almost every limb of the mangrove trees has its noddy tern, and the young are getting about, though unable to fly. On the other half of the island the birds rise in millions, forming a black circling cloud against the sky. ”

“ In the flora, too, the trees and shrubs, the grasses and the herbs, true to their province, retain their botanical individuality, with as much persistence as though separated from their neighbors across the strait, by the broad waters of a mighty ocean and give a contradiction to the doctrines of Darwinism that migration has anything to do with the origin of species, or that natural selection plays any part in permanency of races. ”

“ As these islands, however, are all of that formation, and all of nearly uniform elevation, the evidence is pretty conclusive that upheaval has had no share in the cause of their appearance.
But subsidence of the ocean bed has another and different effect, which causes the appearance of dry land without upheaval. The world is continually shrinking in diameter at the rate of about four feet in a year. The sun’s present rate of contraction, as determined by astronomers, is four miles in a century, that of the earth is one mile in about fourteen centuries. ”

“ If we push a weight, half the strength exerted is in moving the weight, while the other half is spent in holding our feet in position. And so with all forces—the amount spent in accomplishing its object is equalled by the resistance against which the force is acting. Thus, if a volcanic effort were being made at, say Karakatoa, which is the nearest volcanic vent to the Abrolhos, the force expended in the outbreak would be equalled by a recoil acting on some part of the viscid interior of the earth, in the opposite direction to the seat of force. ”

“ The coral insect does not build above water, nor does it build at all in water beyond a moderate depth. How, then, do these coral islands come to exist in their present position?
There are two possible explanations for the existence of these islands. Either the plateau on which they stand has been upheaved, and thus pushed them up from below, or the ocean itself has receded, and left them exposed to the atmosphere. Either of these would have caused the destruction of the insects who build them. A review of the evidence in support of these causes will be of interest. ”

“ This eastern water, of the Australian province, heated by passing over the Australian plateau, is the water into which the captain of the Innsbruck threw his bottle. Thus, while the climate [Pg 39] of Geraldton is tempered by the cool waters of the northern current from the Antarctic Ocean, the Abrolhos have an undue share of warmth transmitted to them by the heated waters of the Pacific as they enter the Indian Ocean. It is this undue share of heat which places these islands in the unique position of being the most southerly coral formations of the world. ”

“ There are a few low shrubs, but on the whole vegetation is scanty. Here considerable quantities of guano have been secured, but the island is now worked out. The island is cut into two by a narrow patch of shoal water, through which we can wade at low tide. Bird life here is almost as numerous as at Rat Island. The western half of Woody Island is a ring of dead coral surrounding a landlocked central lagoon of salt water. The sooty terns’ eggs are scattered all about the margin of this lagoon, and appear to be hatched by the sun’s heat, as we saw none of the birds sitting on the eggs. ”

“ Another point which forcibly strikes an observant visitor to the Abrolhos, is that the mass of most of the islands is composed of dead coral with scare a trace of soil except when the guano deposits have, in a few localities, become mixed with the wind-blown sand, which has enriched such patches so that they now grow stunted shrubs, and on the richer of these patches a species of wild oats, and silver grass, both of which have evidently been introduced. ”

“ Australia, and the whole of what is known as the zoological province of Australia, stands on an ocean plateau which rarely exceeds 100 fathoms in depth; while immediately beyond it, the ocean suddenly attains a depth of from 1000 to 1,200 fathoms. The edge of this plateau is at Lombock Strait, between Lombock and Sambawa Islands, to the east of Java, and passes northerly through the Strait of Macassar, between Celebes and Borneo, thence easterly, embracing the Molucca Islands and New Guinea, and southerly between Australia and New Zealand and embracing Tasmania. ”

“ Here and there on clear patches thousands of the young in all stages of growth are gathered together, covering the whole ground, while a few of the older birds hover about them. It looks like a densely packed feathered school, with their teachers in charge. Every here and there are these schools, while on and under every bush there are stragglers apparently playing truant. The noddy terns are about the size of pigeons, with rich chocolate plumage. They take possession of the bushes, while the sooty terns seem to lay their eggs on the bare ground without any attempt at a nest. ”

“ One cannot sail amongst the Abrolhos group without being struck with the unaltered relative positions in level which they occupy, and, therefore, that their existence to-day is due to subsidences in the ocean’s bed which have taken place in various parts of the world, probably at various periods, to tell us of seismic disturbances of which we otherwise have no record. ”

“ These northerly flowing waters are the cold waters of the Southern Ocean travelling into the equatorial regions, where they are warmed and supply the current which passes westerly and southerly through the Indian Ocean, attaining its greatest velocity as it passes through the Mozambique Channel, thence round the Cape of Good Hope, and north-westerly through the Carribean Sea to form the Gulf stream, which takes a north-easterly course to impart their warm, genial climate to the British islands. ”

“ The channel narrowed till it was not more than three hundred yards or so wide. Pigeon Island lay on our left, with deep water right up to its precipitous rocky bank. The island is one rocky coral mass, with scarce a sign of vegetation. Its surface is covered with mounds of rocks thrown together or built into rough walls gleaming white in the sun, and we are told that these stones were built up as they were removed from the deposit of guano which was worked here. Sixteen hundred tons of this useful manure has been shipped from the island, which has an area of perhaps 200 acres. ”

“ The Runn of Cutch in India, the sinking of the South Island of New Zealand, the disaster at San Francisco, and the catastrophe of Messina, all are the effects of the same forces which result in the sudden alteration of relative levels. ”

“ Going ashore we find it a barren, inhospitable rock—a gull or mollyhawk sits here or there—a few hover about, but there is no sign of the bird life which we were prepared to see here in such abundance. ”

“ Pigeons also are fairly plentiful. Most of these islands are merely banks of dead coral elevated only a few feet above the sea and devoid of vegetation, and on those few exceptions which are capable of supporting animal life, the game at least should be preserved as a possible means of life to shipwrecked or weather-bound crews who may be compelled to remain on them for some time. ”

“ Polar waters always flow towards the equator, still partaking, however, of the westerly direction unless deflected by local causes; and, being cold, flow beneath the warmer currents, which have been expanded by equatorial heat, until, being warmed, they gradually rise and mingle with the equatorial currents, which, in addition to their westerly motion, also flow towards the Poles, till, becoming cooled, they sink and merge with the Polar waters, thus maintaining a continued circulation. ”

“ The wind rose steadily, and by the morning it was blowing a stiff gale, so taking in a reef on the mainsail, we set out for the Pelsart group, some 15 or 20 miles further south. The wind, however, increased, and it was thought advisable to run for shelter into a channel between two bare coral islets near the “Post Office.” Why it is called the “Post Office” it is difficult to understand, for no one lives within miles. On the extremity of one of the islets a beacon of stone has been built, about the size of a sentry box, and it is said that this gave rise to the name. ”

“ The old birds show a strong parental instinct, and resent any interference with their young by cries and savage pecks, but with a little patience they soon become quiet, and will sit beside the young while you place your hand on them. ”

“ The whole surroundings go to prove the truth of the observations of Agassis—that each zoological province has brought forth life best suited to its own chemical and physical environment, without reference to the life already existing in the neighboring provinces. ”

“ We do not know how long this bottle was on the beach before it was discovered, but we may be pretty certain that the longest portion of its period afloat would be after it arrived at the Abrolhos, in battling with the local counter currents which the islands themselves would produce. During the six months which elapsed from the time it left the Innsbruck, it had travelled through 8 degrees of latitude southward and 1-11 of longitude westward—a distance of about 600 miles—in nautical phrase, about south by quarter west. ”