[[p. 461]] The following letter from Mr. Everett to myself was accompanied by a plan and section of one of the caves visited by him and partially excavated. The deposits were as follows:

[[p. 462]] 1. A thin layer of stalagmite
2. Black impure guano . . . 0 ft. 3 in. to 1 ft. 0 in.
3. White clay with Potamides decollatus . . . 1 ft. 0 in. to 2 ft. 6 in.
4. Guano . . . variable
5. Débris of clay and guano, with fragments of limestone and stalagmite in abundance . . . ?2 ft. 0 in. to 3 ft. 0 in.
6. Pure yellow felspathic clay . . . 4 ft. 0 in. to 5 ft. 0 in.
7. Limestone floor.

This particular cave could not be readily worked owing to the influx of water, but other caves exist at higher levels which would be more promising. The expense for six months' work, according to Mr. Everett's estimate, would not be more than the mere passage-money of anyone going out from England. I may add that Mr. Everett quite understands the proper mode of working, having had personal communication with Mr. Pengelly on the subject at Kent's Cavern. He is now thoroughly familiar with the country and the workmen to be employed, and it seems a great pity that advantage should not be taken of his residence in so interesting a locality, the proper exploration of which may throw light on a variety of biological problems.

Alfred R. Wallace

     "You will recollect that some three years ago I came to Sarawak with the object of making general collections of natural history and, more particularly, of investigating the cave-deposits of Borneo.

     "From time to time I made excavations in various caves situated in Upper Sarawak, being assisted pecuniarily by the Rajah to a certain extent. These excavations varied in depth from 4 ft. to 14 ft., and were made in different situations in the caves. No remains of interest, however, were discovered beyond some teeth of a Hystrix, and bones of man, bats, geckoes, &c., in the most superficial deposits, and the only result worth recording was the find of a stone axe-head in a bed of river-gravel. This celt was forwarded to Sir C. Lyell, and such remains as were obtained from the caves were sent to Messrs. Busk and Pengelly at intervals; but the latter, together with a recent tooth of Rhinoceros and two collections of miscellaneous specimens, appear to have been wrongly transhipped in Singapore, and I have never been able to trace their whereabouts.

     "After considerable observation and experience I now wish to state with all frankness my belief that my work was not carried on as it should have been, and that the non-existence of ossiferous deposits in the Bornean caverns is very far from being a proven fact. The inquiry as conducted by myself was not thorough, and it was unsatisfactory partly because I was in serious pecuniary difficulties myself, and partly because what I saw of the poverty of the Government and the remarks I heard dropped about the folly of expending money on such objects made me very shy of taxing the Rajah's liberality. I was, and am still, persuaded that the expense of cave-working in a country like this would have proved very much heavier than the Rajah had any idea of, and hence I worked with inadequate support.

     "In the event of those who are interested in the exploration being desirous of having it continued, I venture to suggest that the person chosen for the work must either possess considerable private means or he must be employed at a regular salary; and further, that the work should be carried on with sufficient funds to render it independent of any assistance the Government here might afford. Money is so scarce here, and public wants so many and pressing, that assistance for purely scientific objects is not to be expected. Coolies are not procurable now under a wage of 2l. a month, and, owing to the rivers being the only roads, travelling expenses are heavy. For tools, lights, gunpowder for blasting, and such preliminary expenses, a sum of 15l. would be sufficient; and the monthly working expenses would vary from 10l. to perhaps as much as 15l., according to the accessibility of the cave to be explored; so that for working a cave for three months a sum of 65l. would probably be required.

     "As I am now employed in the Government service, I do not think I could undertake the work unless a formal application was made to the Rajah for the necessary leave of absence. Even were leave obtained, I do not suppose that I should continue on Government pay, and I could not afford to undertake the work under a salary of 25l. per month. The cheapest way of conducting the exploration would be to send out a gentleman of independent means who would do the work for its own sake, and then only the actual working expenses need be subscribed for. Supposing remains were ultimately found, the item of freight would have to be added to the working expenses.

     "I am induced to write you this letter from reading a note in Nature for June 13, 1872, with regard to the Victoria caves, in which two years of constant but seemingly fruitless work has in the end proved successful. Trusting that another exploration may be attempted in this far more important field, and with like success, I remain, &c.,

"A. Everett
"To A. R. Wallace,
"Sarawak, February 1, 1873"