THE STORY OF THE ISLES OF THE SEA. 337

THE STORY OF THE ISLES OF THE SEA, TOLD BY THE OF THE AIR.

By H. B. TRISTRAM, LL.D., F.R.S., CANON OF DURHAM.

IV.-THE PACIFIC OCEAN. HE story of the Isles of thePacific receives and the Ladrones in the Australian area, T not less illustration from the examination leaving Japan in the , or Pala!arctic of their than does that of the Isles of region; and of course embracing the Sand wich the Indian Ocean. Vast as is the area of the Islands in the Pacific area, which (speaking Pacific, there is, with one exception, that of as a naturalist) does not comprise the Loo­ the Galapagos, a homogeneity in the general choo Islands nor the Aleutian. South-west­ character of its -life, and a distinctness ward from Bali the line runs down beyond withal in the different groups, which separate the west of Australia, where there are no them clearly from each other, and still more islands till we reach the Mascarenes, and widely from the islands of the Indian Ocean. then, sweeping southward, it includes New Nor, although this line of demarcation be­ Zealand, the Chatham Islands, and all the tween the two oceans be apparently arbi­ Oceanic groups in the South Pacific, except­ trary, yet, so far as regards the forms of ing the Galapagos, which are American in insular life, is it other than exact, accurate, their affinities. and sharply defined. If we glance at a map But what are the features which determine of the vast insular region to the south-east "Wallace's line"? To speak of the great of Asia, there is nowhere any visible geo­ families of birds only, on the one side, the graphical break from Malacca to Tasmania. Indian, are the vultures, the pheasants, the One close chain of islands links Australia barbets, the bulbuls, and the true finches, to Asia. with all their innumerable . In fact, But let us examine the teeming bird-life of of the pheasant, barbets, and bulbuls, the that exuberant region, and sup­ Indian region may be said to be the home. plies us with a dividing line, which seems to Not one of them is found on the other side indicate a geologic separation of infinite anti­ of the line. Then the thrushes and the quity. A string of islands runs east of Java warblers (sylviadae), so endless in variety, and to New Guinea, never more than a few miles so numerous in individuals in the old world apart, apparently all of a similar character. of these but a few straggling species cross the There is no special feature to distinguish one line. Most striking of all, the woodpeckers, channel from another. Yet between two of of which there are over three hundred these islands, the observant eye of Mr. A. R. species, are absolutely unknown in the Wallace, who stands at the head of all natu­ Australian region, excepting that some four ralists in scientific exploration, has detected or five species just cross the boundary, and the line which separates India and Australia. are found here and there in Lombok, Celebes, The channel between the small islands of and Moluccas, but not one in Australia or Bali and Lombok is not more than fifteen the Pacific. So much for the great bird­ miles wide, but west of it all life is, speaking families conspicuous for their absence. generally, Indian in its character; east of it, Still more remarkable are the new and un­ all is Australian. From the Himalayas to wonted forms to which we are introduced across Bali, there is no break, only a gradual local the line. They differ infinitely more from the variation in the , birds, reptiles, in­ feathered inhabitants of any other part of the sects, and molluscs. In Lombok the world, than the birds of the rest of the world naturalist finds himself in a . do among themselves. The honeysuckers, a This line of demarcation, now familiar to all of birds remarkable for its structural students of the subject as" Wallace's line," can peculiarities, having a brush at the end of be traced with more or less precision separating its tongue, with which it sweeps up the two entirely distinct portions of the earth's nectar of flowers, and abounding in genera surface. From Bali it runs northwards and species (no less than one hundred and through the straits of Macassar, dividing thirty species are already known), is never Borneo from Celebes, then trending eastward, found out of this Pacific area (if we except it passes between the Philippine Islands on one species which does cross from Lombok the north, and Sanguir to the south, and to Bali), but is represented by numerous further onward embraces the Pelew Islands varieties in every, even the remotest, corner XVIII-24 GOOD WORDS. of that vast space. Other great families are distinct areas of insular bird-life, varying from only feebly developed outside the Austra­ the oldest to the most recent, structurally lian region, but are most characteristic in considered, of the island bird faunas. Standing it. Such are the moreporks (Podargus), out distinctly from all others, the most pecu­ the flower-peckers (Dicaeum), the caterpil­ liar and the oldest in the world, is the most lar eaters (Campephaga), the swallow fly­ recent of England's great colonies, New Zea­ catchers (Artamus), and especially the land, with the Chatham and Auckland Isles, thick-headed shrikes (Pachycephala). Of Lord Howe's, Norfolk, and Philip Islands. birds of universal distribution, the king­ Second, but zoologically far more modern, fishers and the pigeons are here found in a is Australia, with its satellite, Tasmania. variety of species and a gorgeousness of Third in antiquity we may place the Papuan elsewhere unrivalled. But none of region, New Guinea, with Timor, Celebes, these are so strangely diverse from all others Moluccas, and their numerous dependant as are the ostrich-like emeus of Australia, islands. Fourth appear to rank the Sandwich the wingless rails, the resplendent rifle- birds, Islands. Fifth, by far the widest in area, the the gorgeous birds of paradise of Papua, Polynesian Archipelago, with countless islets, bower-birds, lyre-birds, and most of all, the scattered over ninety degrees of longitude weird-like kiwi or Apteryx and the recently and forty of latitude, from the Pelew Islands exterminated colossal (Dinornis) of to Easter Island. Lastly we have the most New Zealand. modern of all, the Galapagos, which might, What is the story of the isles which perhaps, be more justly treated as an outlier all this tells? Why, without any sudden of South America, but the exceptional natural change of climate, with no perceptible differ­ history of which casts much light on the ence in geologic character, should that line variation and specialisation of species. of Wallace prove a great barrier, which these The Galapagos Islands, lying just under birds pass neither one way nor the other? It the equator, six hundred miles westward of cannot be want of power of flight, for all, South America, are a striking contrast in excepting the brevi pennant or wingless their general character and appearance to species, cross infinitely wider expanses of other tropical islands. Spread over a space water elsewhere. It tells us, surely, that the of two hundred miles from north to south, Australian region is no mere prolongation of and one hundred and eighty from east to Eastern Asia, but that, while there has been, west, they are wholly volcanic. On many whatever may have been from time to time of them the volcanoes are still active, and the oscillations, upheavals, or depressions of one crater attains a height of four thousand the earth's surface, more or less communi­ seven hundred feet. The streams of lava cation between the whole Indian region as have sometimes so heated the water as to far as Bali, from a period infinitely more compel ships to run from their anchorage, remote, the sea has ever flowed between that where they found a sea temperature of 150° and island and Lombok, and no upheaval has the atmosphere 147°. Notwithstanding these ever united them; that the fissure between occasional irregularities, the temperature is them is one that has probably existed ever usually moderate for an equatorial region, since the crust of the earth first solidified. If, for the Galapagos are struck by the polar cur- as in the course of these papers we shall rent from the south. From the same cause, endeavour to show, the bird-life of these probably, there is a total absence of the islands is really the most antique on the face coralline insects, so universal elsewhere of the earth, it seems difficult indeed to round the Pacific Islands. avoid this conclusion, or not to admit that But even this is scarcely enough to ac­ here ornithology actually demonstrates a count for the strange barrenness, the mea­ great geological fact, which neither the com­ greness of vegetation, its stunted growth, for position of the rocks nor any palreontological the most part wretched little weeds, more traces could have suggested. becoming an arctic than an equatorial When we proceed to classify and group the flora, and for the abnormal absence of birds of these islands, scattered over one­ brilliant colours, both in and vege­ third of the earth's surface, we find differ­ table life. The largest island of the group, ences so great and so marked that we are Albemarle, eighty miles in length and in one led to suggest that the Pacific region is but part fifty miles wide, is, excepting on its a comprehensive term for various areas not southern side, miserably barren, covered less distinct than the other natural regions of with immense streams of black naked lava, the globe. We may fairly count six such and studded with craters. The island of THE STORY OF THE ISLES OF THE SEA. 339

Narborough seems even more repulsive, its tion for sea store during two centuries, only signs of life being a few mangrove-trees first by buccaneers and then by whalers. near the shore. Mr. Darwin has remarked In many of the isles not a tortoise is left, but that probably there is not within the whole in others there are still a few of these huge range of the tropics another region so sterile. Chelonians, weighing sometimes two hundred Yet there is no lack of moisture. Although and fifty pounds, and some of them requiring rain falls plentifully but at one season, the united efforts of six or eight men to lift the clouds generally hang low and the them. As they creep along at the rate of hills are well clothed with verdure. six yards a minute or four miles a day, taking Again, had we any reason to believe the no notice of the human intruder beyond islands to be geologically recent, it might be drawing in their heads with a low hiss, they supposed that stragglers from the neighbour­ recall some ungainly monster of the old repti­ ing continent had not yet had time to settle lian age, which has escaped destruction in this and extend themselves. But the whole ap­ hidden nook, and survives to tell of what pearance of the rocks forbids this. There sort were once the lords of creation. It is are few volcanic regions whose cliffs indicate curious that, while it is threatened with exter­ a greater antiquity, in the different strata of mination in its native haunts, this tortoise lava currents to be traced in their sections, has been transplanted by whalers to various and the evident length of time which must other parts of the globe, and is now found have elapsed between the various torrents. in India and elsewhere. From the whole structute of the islands, from As in Mauritius, it is not so much the the depth of the oceanic depression be­ active agency of man, but the turning loose tween them and South America, it is impos­ of pigs, which forebodes the early exter­ sible to hold that they have ever had any mination of the native fauna. Here, as else­ closer connection with South America than where, pigs have become wild, and thousands they have at present. They rise from an upon thousands of the and young of the area of depression beyond that great axis of great tortoise are annually devoured by them. elevation, the Andes chain, which has pro­ Pigs, asses, goats, and cattle have all been bably been such an axis ever since the earth turned out, and, taking to the hills and woods solidified and assumed its present shape-the of the more fertile islands, have multiplied complement, in fact, of the Pacific area. of exceedingly. There seems to be but one depression. native quadruped, a little rodent, peculiar, Yet these dreary and unattractive cinder but allied to the South American forms. heaps are, both in their plants and their Man, however, has signally failed in his animals, a little world oy itself. They have attempts to settle himself. A Peruvian con- nothing in common with any other Pacific vict settlement was planted more than forty island. In examining their living inhabitants years ago, but it has dwindled to one or two we have the satisfaction of believing that, un­ families, who subsist by supplying whalers. like the case of the Mascarenes, though man This the naturalist has no cause to regret, has begun the work of destruction, he has in for it has preserved for his study almost the no case, as yet, accomplished that of extermi­ last insular fauna surviving in its entirety. nation. Though the trees be stunted, the This, strange to say, was never noticed till plants mean, and the birds sombre, they are the visit of Mr. Darwin in 1835. That visit not the relics of a more abundant flora and has made the Galapagos classic soil. Here fauna. The forbidding appearance of the were first suggested to him those problems land discouraged any early attempts at colo­ on the derivative origin of species, and their nisation, though the group was known about , the various attempted solutions of the middle of the sixteenth century. But which have revolutionised, within a very few they were found a very convenient rendez­ years, the whole science of natural history. vous and watering place by the English buc­ The birds, with whom we have to do, for caneers, who would seem to have been almost the tortoises are a digression, are what most their only visitors for about a century and a clearly revealed to the philosopher the story half. In this capacity Dampier visited and of the isles of the sea. The visits of the described them in 1684. buccaneers had been long forgotten, the calls The most valued and famous product of of the whalers had evidently made no im­ the islands were then, as still, the gigantic pression on these aborigines. The seamen tortoises or land turtles, once found in in­ had probably confined their hunting to the credible plenty, but now rapidly becoming great tortoises, and, unlike a French sports­ extinct, partly from the wholesale destruc- man, had scorned to notice sparrows or 340 GOOD WORDS. thrushes. These welcomed Mr. Darwin and geant of Mauritius, or the huge Notornis his companions with a confidence which" his of New Zealand, we find the most diminutive form with indifference scanned." So tame of its family, a bird barely four inches long, and unsuspecting were they, that they did and a microcosm of the great rails (Aramides) not understand what was meant by stones of South America. An insular position here being thrown at them, they allowed them­ evidently does not foster development of selves to be struck down one after another by size. The white owl too, though it has lost a boy with a stick, and on one occasion, "a its whiteness, while the barn owl of Poly­ mocking-bird alighted on the edge of a nesia only differs from our own in the greater pitcher which I held in my hand, and began purity of its plumage, is smaller than any quietly to sip the water, and allowed me to other variety of this cosmopolitan bird. lift it with the vessel from the ground." This Equally exceptional is the fact, that while is exactly the experience of the Dutch in the same gulls and petrels roam over the Mauritius, of Leguat in Rodriguez, and of whole of the rest of the vast area of the Captain John Smith among the shearwaters Pacific, peculiar and sombre-coloured species of Bermuda, when he "went about among are found confined to these island shores. them and felt them, to eschew the lean and The" genera" or groups of species belong­ choose the fat." Nor was this tameness a ing exclusively to the Galapagos are abso­ peculiarity of certain species. Hawks, owls, lutely unique; yet they have more affinity to and pigeons showed the same absence of fear the American than to any other groups of as finches or thrushes. birds. They are some of them structurally If we analyze the collections that have related to the American Caereba; others more been made on the Galapagos, we shall find like buntings. But whatever they be struc­ that out of thirty species of birds of prey and turally, in colour and proportions all the passerine birds, only one species is found genera are strangely alike. They are all elsewhere, and that is the American -bird, brown, or brown-mottled, with the old males a well-known migrant, spread over the whole sometimes black. Of these peculiar genera of North America, and of the southern con­ there are known nineteen species. Some of tinent as far as the equator. Besides these, these may perhaps blend into each other, or be the one pigeon and the one are peculiar, the peculiar races of particular islands. But and stranger still, of three of the heron family the examination has been so hasty, that it is two are peculiar; the only two species of very probable other species still remain un- gull, the only two species of petrel, and the noticed. Whatever the form of the bill, be one penguin (the most northerly species of it that of a grosbeak or a warbler, they have the family), are all peculiar. This isolation short wings, strong legs, and very dumpy of species of oceanic birds with the vast tails. Yet their continental relatives are powers of flight of gulls and petrels, is, I among the most gorgeously decked birds in believe, without parallel. The other birds the world, and generally with long tails. that occur are , plover, and sandpipers, Again, as if to controvert the very natural of course all migrants and visitors, and hypothesis that the Galapagos were colonised found all along the west coast of America. from South America, there is a remarkable All the fifty-seven species found here may absence of the great families of birds which be classed under thirty-nine genera, of which characterize that continent. Of the humming­ twenty-seven are almost world·wide, five are bird, whose very cradle is the Andes, with peculiar to the Galapagos, and seven belong its five hundred species, not a solitary also to continental America. It is here that straggler occurs in the Galapagos. Yet other we obtain our key to the zoological relation­ islands nearer the coast, in climates far more ships of " this little world within itself," as inclement, are rich in these jewelled beauties. Mr. Darwin aptly terms it There is a re­ Juan Fernandez has three species of its markable absence of anything suggestive of own, and one extends even to Queen Char­ relationship with the rest of the Pacific. lotte Island and Nootka Sound. Of the There is no honeybird, no flower-pecker, no tanagers, the tree-creepers (Dendrocolaptes), shrike, no kingfisher, no parrot. The one and the ant-hunters (Formicaria), the orni­ dove, peculiar though it be, has nought in thological features of South America, not a common with the innumerable pigeons, in specimen is found. fairy-like plumage, of the South Sea Islands. Whence, then, asked Mr. Darwin, are the It is unmistakably American in its type. Galapagos peopled? and why are they not The same is true of the herons. Then comes only a world within themselves-for this is the little water-rail. Instead of the whilom true, as we have seen, of other Oceanic islands 341

-but why, being so, do they differ from that North, not South, America has supplied other tropical island worlds, in the absence from time to time the progenitors of its bird of colour and the pigmy stature of their inhabitants-that the Galapagos have been inhabitants? It has been shown that these thrown up from the ocean depths long sub­ had not to struggle for existence against sequent to the Andean ranges, but yet at so enemies, the absence of which might be sup­ remote a period that the cold polar current, posed to explain the giant stature of the the humid atmosphere, and the barren soil pigeons, parrots, or rails of the Mascarenes. have had time gradually to obliterate all The formation of the islands forbids the traces of colour in plumage, except in the hypothesis that they are the relics of a sub­ more recent arrivals (one of which, the rice­ merged continent; their fauna, therefore, bird, has not had time to modify at all), and must be derivative. We have seen it is not that scanty food has tended to stunt the de­ Polynesian; it can only, then, be American. velopment of individual size. The excep­ But it is not South American specially; it tional stoutness and strength of feet may be would seem rather to be derived from the accounted for by the roughness of the soil. western side of California. There is nothing, As to the universal abbreviation of the tail, as in the islands of the Indian Ocean, or in we are not prepared with any conjecture on New Zealand, to suggest the idea of the the cause of this sumptuary curtailment. feeble remains of a bygone age of ornithic The story, then, of the Galapagos, as told supremacy. Its" ornis" is essentially mo­ by its birds, is, that it is geologically the most dern in type, while its gigantic tortoises and recent of the Oceanic groups of the Pacific, is its huge, hideous black lizards, both land connected with none other, and has been and water, attaining a height of four feet, peopled from the north-east rather than from prove that there is nothing in the nature of the opposite coast. the region to prohibit the development of From the Galapagos we pass upwards and animals to an exceptional size. onwards, geographically, and almost, we The only solution, so far, seems to be that the may say, chronologically, to the Sandwich reptiles are the earliest occupants of the soil- Islands.