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eater (Nyctiornis amicta), the great gaper (Corydon sumatranus), and the green-crested gaper (Calyptomena viridis), and many others, which are common to Malacca, Sumatra, and Borneo, but are entirely absent from Java. On the other hand we have the peacock, the green jungle-cock, two blue ground-thrushes (Arrenga cyanea and Myophonus flavirostris), the fine pink-headed dove (Ptilonopus porphyreus), three broad-tailed ground-pigeons (Macropygia), and many other interesting birds, which are found nowhere in the Archipelago out of Java.

Insects furnish us with similar facts wherever sufficient data are to be had, but owing to the abundant collections that have been made in Java, an unfair preponderance may be given to that island. This does not, however, seem to be the case with the true Papilionidæ, or swallow-tailed butterflies, whose large size and gorgeous coloring has led to their being collected more frequently than other insects. Twentyseven species are known from Java, twenty-nine from Borneo, and only twenty-one from Sumatra. Four are entirely confined to Java, while only two are peculiar to Borneo and one to Sumatra. The isolation of Java will, however, be best shown by grouping the islands in pairs, and indicating the number of species common to each pair. Thus :

Making some allowance for our imperfect knowledge of the Sumatran species, we see that Java is more isolated from the two larger islands than they are from each other, thus entirely confirming the results given by the distribution of birds and Mammalia, and rendering it almost certain that the last-named island was the first to be completely separated from the Asiatic continent, and that the native tradition of its having been recently separated from Sumatra is entirely without foundation.

We are now enabled to trace out with some probability the course of events. Beginning at the time when the whole

of the Java sea, the Gulf of Siam, and the Straits of Malacca were dry land, forming, with Borneo, Sumatra, and Java, a vast southern prolongation of the Asiatic continent, the first movement would be the sinking down of the Java sea and the Straits of Sunda, consequent on the activity of the Javanese volcanoes along the southern extremity of the land, and leading to the complete separation of that island. As the volcanic belt of Java and Sumatra increased in activity, more and more of the land was submerged, till first Borneo, and afterward Sumatra, became entirely severed. Since the epoch of the first disturbance, several distinct elevations and depressions may have taken place, and the islands may have been more than once joined with each other or with the main-land, and again separated. Successive waves of immigration may thus have modified their animal productions, and led to those anomalies in distribution which are so difficult to account for by any single operation of elevation or submergence. The form of Borneo, consisting of radiating mountain chains with intervening broad alluvial valleys, suggests the idea that it has once been much more submerged than it is at present (when it would have somewhat resembled Celebes or Gilolo in outline), and has been increased to its present dimensions by the filling up of its gulfs with sedimentary matter, assisted by gradual elevation of the land. Sumatra has also been evidently much increased in size by the formation of alluvial plains along its north-eastern coasts.

There is one peculiarity in the productions of Java that is very puzzling the occurrence of several species or groups characteristic of the Siamese countries or of India, but which do not occur in Borneo or Sumatra. Among mammals the Rhinoceros javanicus is the most striking example, for a distinct species is found in Borneo and Sumatra, while the Javanese species occurs in Birmah and even in Bengal. Among birds, the small ground-dove (Geopelia striata) and the curi ous bronze-colored magpie (Crypsirhina varians) are common to Java and Siam; while there are in Java species of Pteruthius, Arrenga, Myiophonus, Zoothera, Sturnopastor, and Estrelda, the nearest allies of which are found in various parts of India, while nothing like them is known to inhabit Borneo or Sumatra.

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Such a curious phenomenon as this can only be understood by supposing that, subsequent to the separation of Java, Borneo became almost entirely submerged, and on its re-elevation was for a time connected with the Malay Peninsula and Sumatra, but not with Java or Siam. Any geologist who knows how strata have been contorted and tilted up, and how elevations and depressions must often have occurred alternately, not once or twice only, but scores and even hundreds of times, will have no difficulty in admitting that such changes as have been here indicated are not in themselves improbable. The existence of extensive coal-beds in Borneo and Sumatra, of such recent origin that the leaves which abound in their shales are scarcely distinguishable from those of the forests which now cover the country, proves that such changes of level actually did take place; and it is a matter of much interest, both to the geologist and to the philosophic naturalist, to be able to form some conception of the order of those changes, and to understand how they may have resulted in the actual distribution of animal life in these countries—a distribution which often presents phenomena so strange and contradictory that, without taking such changes into consideration, we are unable even to imagine how they could have been brought about.

THE islands of Bali and Lombock, situated at the east end of Java, are particularly interesting. They are the only isl ands of the whole Archipelago in which the Hindoo religion still maintains itself, and they form the extreme points of the two great zoological divisions of the eastern hemisphere; for although so similar in external appearance and in all physical features, they differ greatly in their natural productions. It was after having spent two years in Borneo, Malacca, and Singapore that I made a somewhat involuntary visit to these islands on my way to Macassar. Had I been able to obtain a passage direct to that place from Singapore, I should probably never have gone near them, and should have missed some of the most important discoveries of my whole expedition to the East.

It was on the 13th of June, 1856, after a twenty days' passage from Singapore in the "Kembang Djepoon" (Rose of Japan), a schooner belonging to a Chinese merchant, manned by a Javanese crew, and commanded by an English captain, that we cast anchor in the dangerous roadstead of Bileling, on the north side of the island of Bali. Going on shore with the captain and the Chinese supercargo, I was at once introduced to a novel and interesting scene. We went first to the house of the Chinese bandar, or chief merchant, where we found a number of natives, well dressed, and all conspicuously armed with krisses, displaying their large handles of ivory or gold, or beautifully grained and polished wood.

The Chinamen had given up their national costume and adopted the Malay dress, and could then hardly be distinguished from the natives of the island-an indication of the close affinity of the Malayan and Mongolian races. Under the thick

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161 shade of some mango-trees close by the house, several womenmerchants were selling cotton goods; for here the women trade and work for the benefit of their husbands, a custom which Mohammedan Malays never adopt. Fruit, tea, cakes, and sweetmeats were brought us; many questions were asked about our business and the state of trade in Singapore, and we then took a walk to look at the village. It was a very dull and dreary place; a collection of narrow lanes bounded by high mud walls, inclosing bamboo houses, into some of which we entered, and were very kindly received.

During the two days that we remained here I walked out into the surrounding country to catch insects, shoot birds, and spy out the nakedness or fertility of the land. I was both astonished and delighted; for as my visit to Java was some years later, I had never beheld so beautiful and well cultivated a district out of Europe. A slightly undulating plain extends from the sea-coast about ten or twelve miles inland, where it is bounded by a fine range of wooded and cultivated hills. Houses and villages, marked out by dense clumps of cocoanut palms, tamarind and other fruit-trees, are dotted about in every direction; while between them extend luxuriant ricegrounds, watered by an elaborate system of irrigation that would be the pride of the best cultivated parts of Europe. The whole surface of the country is divided into irregular patches, following the undulations of the ground, from many acres to a few perches in extent, each of which is itself perfectly level, but stands a few inches or several feet above or below those adjacent to it. Every one of these patches can be flooded or drained at will by means of a system of ditches and small channels, into which are diverted the whole of the streams that descend from the mountains. Every patch now bore crops in various stages of growth, some almost ready for cutting, and all in the most flourishing condition and of the most exquisite green tints.

The sides of the lanes and bridle-roads were often edged with prickly Cacti and a leafless Euphorbia, but the country being so highly cultivated there was not much room for indigenous vegetation, except upon the sea-beach. We saw plenty of the fine race of domestic cattle descended from the Bosbanteng of Java, driven by half-naked boys, or tethered in