Batchian is remarkable as being the most eastern point on the globe inhabited by any of the Quadrumana. A large black baboon-monkey (Cynopithecus nigrescens) is abundant in some parts of the forest. This animal has bare red callosities， and a rudimentary tail about an inch long--a mere fleshy tubercle， which may be very easily overlooked. It is the same species that is found all over the forests of Celebes， and as none of the other Mammalia of that island extend into Batchian I am inclined to suppose that this species has been accidentally introduced by the roaming Malays， who often carry about with them tame monkeys and other animals. This is rendered more probable by the fact that the animal is not found in Gilolo， which is only separated from Batchian by a very narrow strait. The introduction may have been very recent， as in a fertile and unoccupied island such an animal would multiply rapidly. The only other mammals obtained were an Eastern opossum， which Dr. Gray has described as Cuscus ornatus；the little flying opossum， Belideus ariel； a Civet cat， Viverra zebetha； and nice species of bats， most of the smaller ones being caught in the dusk with my butterfly net as they flew about before the house.
After much delay， owing to bad weather and the illness of one of my men， I determined to visit Kasserota (formerly the chief village)， situated up a small stream， on an island close to the north coast of Batchian； where I was told that many rare birds were found. After my boat was loaded and everything ready， three days of heavy squalls prevented our starting， and it was not till the 21st of March that we got away. Early next morning we entered the little river， and in about an hour we reached the Sultan's house， which I had obtained permission to use. It was situated on the bank of the river， and surrounded by a forest of fruit trees， among which were some of the very loftiest and most graceful cocoa-nut palms I have ever seen. It rained nearly all that day， and I could do little but unload and unpack. Towards the afternoon it cleared up， and I attempted to explore in various directions， but found to my disgust that the only path was a perfect mud swamp， along which it was almost impossible to walk， and the surrounding forest so damp and dark as to promise little in the way of insects. I found too on inquiry that the people here made no clearings， living entirely on sago， fruit， fish， and game； and the path only led to- a steep rocky mountain equally impracticable and unproductive. The next day I sent my men to this hill， hoping it might produce some good birds； but they returned with only two common species， and I myself had been able to get nothing； every little track I had attempted to follow leading to a dense sago swamp. I saw that I should waste time by staying here， and determined to leave the following day.
This is one of those spots so hard for the European naturalist to conceive， where with all the riches of a tropical vegetation， and partly perhaps from the very luxuriance of that vegetation， insects are as scarce as in the most barren parts of Europe， and hardly more conspicuous. In temperate climates there is a tolerable uniformity in the distribution of insects over those parts of a country in which there is a similarity in the vegetation， any deficiency being easily accounted for by the absence of wood or uniformity of surface. The traveller hastily passing through such a country can at once pick out a collecting ground which will afford him a fair notion of its entomology.
Here the case is different. There are certain requisites of a good collecting ground which can only be ascertained to exist by some days' search in the vicinity of each village. In some places there is no virgin forest， as at Djilolo and Sahoe； in others there are no open pathways or clearings， as here. At Batchian there are only two tolerable collecting places，--the road to the coal mines， and the new clearings made by the Tomóre people， the latter being by far the most productive. I believe the fact to be that insects are pretty uniformly distributed over these countries (where the forests have not been cleared away)， and are so scarce in any one spot that searching for them is almost useless. If the forest is all cleared away， almost all the insects disappear with it； but when small clearings and paths are made， the fallen trees in various stages of drying and decay， the rotting leaves， the loosening bark and the fungoid growths upon it， together with the flowers that appear in much greater abundance where the light is admitted， are so many attractions to the insects for miles around， and cause a wonderful accumulation of species and individuals. When the entomologist can discover such a spot， he does more in a mouth than he could possibly do by a year's search in the depths of the undisturbed forest.
The next morning we left early， and reached the mouth of the little river in about au hour. It flows through a perfectly flat alluvial plain， but there are hills which approach it near the mouth. Towards the lower part， in a swamp where the salt-water must enter at high tides， were a number of elegant tree-ferns from eight to fifteen feet high. These are generally considered to be mountain plants， and rarely to occur on the equator at an elevation of less than one or two thousand feet. In Borneo， in the Aru Islands， and on the banks of the Amazon， I have observed them at the level of the sea， and think it probable that the altitude supposed to be requisite for them may have been deduced from facts observed in countries where the plains and lowlands are largely cultivated， and most of the indigenous vegetation destroyed. Such is the case in most parts of Java， India， Jamaica， and Brazil， where the vegetation of the tropics has been most fully explored.