scored by many steep-sided valleys, and the green of the fields contrasting brightly with the red volcanic earth. Behind these nearer hills one of the great conical mountains loomed out every now and then from his covering of clouds. To the westward, and more distant, a high volcanic peak on the main island of Sumatra rose above nearer islands, and later in the afternoon we saw the simple conical mass of Krakatao. Next day we were bouncing about in deep blue water, as we steamed south against a head-wind -a change after the quiet sailing over the pale green shallow seas in which we had been since we entered the Straits of Malacca. On Friday, September 30, we reached Christmas Island. The first we saw of it was a long line against the south-east horizon, with a shallow saddle in the middle and a gradual rise at either end that to the west being the higher. On nearer approach the island was seen to be uniformly covered with trees, with a low cliff, much undermined at the water's edge; above this a gradual slope leads to another steep ascent, which in some places, especially at the projecting headlands, is a bare cliff, in others covered with trees. From this there is a gradual rise to the top. We found that there is a cap of coral limestone over the whole island. The top is formed of gray pinnacled masses with steep fissures between them, and the surface of the rock is worn into a rough honeycomb with sharp points and ridges which break under foot and show the glistening white rock. On the slope of the island this rock forms horizontal terraces, with a rough slope of pinnacled masses or a sheer cliff leading down from them, and these seemed to be in a general way continuous at the same level along the side of the island. I suppose they mark the pauses in its gradual elevation during which a fringing reef has formed. Some pieces of rock, apparently volcanic, were picked up at Flying-fish Cove, but it was not found where they had fallen from.

"No stream or standing water was found. Apparently all the rain that falls soaks into the porous rock at once. The vegetation, however, looked fresh and green, and the under parts of fallen logs were sodden with moisture. On two of the nights during the ten days we were there, there was heavy rain; otherwise we had fine weather. Many of the trees are tall, reaching one hundred and fifty to one hundred and seventy feet or more, and some of them have vertical buttresses at the base, which wind about horizontally

and give off secondary buttresses. They are often laden with great clumps of birds'nest ferns, as well as with other ferns, orchids, and parasitical trees, and their trunks are festooned with long straight lianas. I only found two orchids with flowers out, and these were small and inconspicuous. Along the shore there are tangled thickets of screw pines, and another kind grows on the higher part. A large proportion of the trees bear edible fruits. Altogether I am sending home some fifty kinds of flowering plants and fifteen of ferns.

"The rat (Mus macleari) swarms on the island. They came out at dusk, and ran about, in and out of the tents that were pitched by the shore, through the night. There is another kind of rat which is larger and black, except where the scanty fur on the feet allows the pale skin to show. There is also a shrew mouse, whose short shrill squeak may often be heard in the woods. I caught three of them one night in a pitfall. Several specimens of the fruit-eating bat (Pteropus natalis) were obtained, including males, which have no pale-colored tippet, as Mr. Thomas [P. Z. S., 1887, p. 512] thought might possibly be the case. There is a small insectivorous bat in the island, but I did not succeed in getting one.

"The large fruit-eating pigeon (Carpo phaga whartoni) is very common. They congregate in the fruit-bearing trees, and may then be shot by the dozen. They are excellent eating, and supplied fresh meat for the ship.

"There is a small dove - brown, with a rich bronzy-green on the back and wings

which is very common. Their habits are remarkably in keeping with their coloring. On trees they are restless and sel dom seen, but on the ground, among fallen brown and green leaves, where their color makes them very inconspicuous, they seem to have no fear. I shot seven one morning close to our place; they were feeding in pairs on fallen berries, and when one of a pair was shot, the other went on feeding as though nothing had happened.

The thrush (Turdus erythropleurus) is very abundant, and as tame as possible. None of my specimens show any mottling, but Captain Aldrich told me that he saw one with the breast mottled. The bill and feet are as yellow as a cock blackbird's. I heard no song, but they often give a chickchick chick-chick-chick -chick,' quickening time at the finish.

"Parties of twelve to twenty of a species

of Zosterops were very common. They had just-fledged young ones among them. "The other birds we obtained were two hawks, an owl, a swift, a heron, a plover, and a sandpiper. Besides these, frigatebirds, gannets, boobies, and boatswainbirds of two kinds were everywhere abundant.

"We obtained three kinds of lizards, and the Typhlops which was found before, but no tortoises. We saw a turtle making off down the beach early one morning, but it got into the sea before it could be turned

Accounts have been received from Captain Aldrich, R.N., of H.M. surveying vessel Egeria, of a recent visit to Christmas Island in the Indian Ocean, made in consequence of the interest attaching to the small collection recently brought thence by Captain Maclear, R.N. (see Nature, vol. xxxvi., p. 12). Mr. J. J. Lister kindly volunteered to act as naturalist, and proceeded from England to Colombo, whence he took a passage in the Egeria for the purpose of collecting.

Captain Aldrich states that the highest point of the island was reached at the expense of considerable labor, but without as much difficulty as was anticipated. This point is twelve hundred feet high, and not, as was before incorrectly stated, fifteen hundred and eighty feet.

The island is coral-clad to the very top, the actual summit being a block of coralline limestone, worn and undermined. No rock other than of a calcareous nature was met with in the island, though a diligent search was made, and holes dug where the soil appeared thickest.

Three tiers of cliffs, probably marking sea-levels, intervene between the top of the existing sea cliffs and the summit. Breaches in these cliffs afforded means of scaling them, aided by the numerous aërial roots of the trees with which the island is densely covered.

Between the cliffs the ground rises ir regularly, being covered in some places with soil apparently deep, intermixed with fragments of coral. Tangled jungle and high forest grow everywhere. The vertical rise to the summit where ascended

The total horizontal distance is about five thousand feet.

Christmas Island therefore appears to be a remarkable instance of the complete casing with coral of an island which, from the time that its nucleus first came within the reef-building zone, has been steadily subjected to a movement of upheaval, varied by pauses, during which the cliffs were eroded by the sea. So far as I am aware, no case of similar magnitude has yet been recorded.

The collections now on their way to England are, it is feared, not so varied as was anticipated from the samples of life brought home by the Flying Fish.

A considerable number of interesting photographs were obtained by the officers, and accompany Captain Aldrich's report, which will be published.

The Egeria has obtained a line of soundings across the hitherto unfathomed area of the southern Indian Ocean, between the Strait of Sunda and Mauritius, but no details have as yet come to hand.

December 17.

W. J. L. WHARTON.

THERE is nothing more wonderful in nature than the power of flight possessed by birds, and no subject which yields more startling facts upon investigation. "The way of an eagle in the air" is one of those things of which Solomon expressed himself ignorant; and there is something truly marvellous in the mechanism which con. trols the scythe-like sweep of wings peculiar to most birds of prey. Yet even naturalists of the first order have had little or nothing to say about the power of flight in birds, while some of them speak on very insufficient evidence. Witness Michelet's statement that the swallow flies at the rate of eighty leagues an hour. Roughly, this gives us a thousand miles in four hours; but assuredly, even in its

swiftest dashes, the swallow does not at- | tain to anything like this speed. But the Duke of Argyll is rather under than over the mark when he computes the speed at more than a hundred miles an hour. The mechanism of flight in the swallows is carried through an ascending scale, until in the swift it reaches its highest degree of power, both in endurance and facility of evolution. Although there are birds which may and probably do attain to the speed of a hundred and fifty miles an hour, this remarkable rate is not to be looked for in any of the birds of the swallow kind. In their migration swallows stick close to land, and never leave it unless compelled. They cross straits at the narrowest part, and are among the most fatigable of birds. Apparently, though they may possess considerable speed, they have no great powers of sustained flight. These attributes belong in the most remarkable degree to certain ocean birds.

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Any one who has crossed the Atlantic must have noticed that gulls accompany the ship over the whole distance -or at least are never absent. The snowy sea swallows," as the terns are called, seem quite tireless; though the petrels and albatrosses alone deserve the name of oceanic birds. No sea-deserts seem to bound the range of the petrels, and they are found at every distance from land. Different species haunt different seas from the fulmar in the far north, to the giant petrel which extends its flight to the ice banks of the south. Here the Antarctic and snowy petrels appear, often floating upon the drift-ice, and never leaving these dreary seas. Another bird of immense wing power is the tiny stormy petrel, the smallest web-footed bird known. It belongs to every sea; and although so seeming-frail it breasts the utmost fury of the storm, skimming with incredible velocity the trough of the waves and gliding rapidly over their crests. Petrels have been observed two thousand miles from nearest land, whilst at half that distance Sir James Ross once saw a couple of penguins paddling in the sea. A pair of the rudimentary wings of this bird are lying before me as I write. They are simply featherless paddles; but so rapidly does the bird swim by their aid, that all of the fishes do not go at equal speed. The enormous appetite of the giant penguin (which weighs about eighty pounds) may have something to do with its restricted powers of flight In the stomach of one of these birds Ross found ten pounds of quartz granite and trap fragments-swallowed most likely to

promote digestion. The lord of the winged race is the frigate-bird. He is a navigator who never reaches his bourne; his flight seems almost ceaseless. To a bird with such superb wing-apparatus the metaphor "he sleeps upon the storm" almost becomes literal. This black solitary bird is little more than wing, his pinions measur ing fifteen feet- even surpassing those of the condor of the Andes. Although sometimes seen four hundred leagues from land, the frigate-bird is said to return every night to its solitary roost. But these birds and the wandering albatross are sea and ocean species, and with rare exceptions are able to rest upon the waters. This, however, cannot be said of many of the land birds, and here observation is easier.

This

Thousands of gold-crests annually cross and recross the North Sea at the wildest period of the year, and, unless the weather is hazy, generally make their migrations in safety. And yet this is the smallest and frailest British bird-a mere fluff of feathers, weighing only seventy grains. Another of the tits, the oxeye, has been met upon two occasions at six hundred and nine hundred miles from land. With regard to the birds which cross the At lantic, it matters not for our purpose whether they are driven by stress of weather or cross voluntarily; it suffices that they come. The American passenger pigeon accomplishes the distance, and so does the purple martin. The speed of flight in the former is approximately known; it is able to cover sixteen hundred miles in twenty-four hours. seems marvellous when we reflect that, flying at the rate of nearly seventy miles an hour, it takes the bird two days and nights to cross. What must be the mechanism that can stand such a strain as this? In the Anglo-Belgian pigeon-races some of the birds attain to a speed of nearly a mile a minute; and this when the race is for five hundred miles. The English, French, and Germans all rear pigeons in their fortresses; the birds are also employed by the Trinity House in conveying messages from the lightships, and they are used on the Indian stations. Two facts taken in conjunction are significant. The Germans are training pigeons to carry messages; the Russians are training falcons to catch pigeons. The noblest of the birds of prey, the peregrine, has been seen flying over mid-Atlantic; and I have known a bird of this species, when in perfect training, to fly thirteen hundred and fifty miles in a little over twen