Narrative of the surveying voyages of his majesty's ships Adventure and Beagle (vol.3)

552 KEELING ISLAND. April, 1836. a visit to the sea, no doubt for the purpose of moistening its branchiae. The young are likewise hatched, and live for some time, on the coast. These crabs inhabit deep burrows, which they excavate beneath the roots of trees ; and here they accumulate surprising quantities of the picked fibres of the cocoa-nut husk, on which they rest as on a bed. The Malays sometimes take advantage of their labour by collecting the course fibrous substance and using it as junk. These crabs are very good to eat ; moreover under the tail of the larger ones there is a great mass of fat, which when melted sometimes yields as much as a quart bottle full of limpid oil. It has been stated by some authors that the Birgos latro crawls up the cocoa-nut trees for the purpose of stealing the nuts : I very much doubt the possibility of this ; but with the Pandanus"^- the task would be very much easier. I under- stood from Mr. Liesk that on these islands the Birgos lives only on the nuts which fall to the ground. I was a good deal surprised by finding two species of coral of the genus Millepora, possessed of the property of sting- ing. The stony branches or plates when taken fresh from the water have a harsh feel and are not slimy, although possess- ing a strong and disagreeable odour. The stinging property seems to vary within certain limits in different specimens when a piece was pressed or rubbed on the tender skin of the face or arm, a pricking sensation was generally caused, which came on after the interval of a second, and lasted only for a short time. One day, however, by merely touching my face with one of the branches the pain was instantaneous ; it increased as usual after a few seconds, and remaining sharp for some minutes, was perceptible for half an hour afterwards. The sensation was as bad as that from a nettle, but more like that caused by the Portuguese man-of-war {Physalia). Little red spots were produced on the tender skin of the arm, which appeared as if they would have formed watery pustules, but did not. The circumstance of this sting- * See Proceedings of Zoological Society, 1832, p. 17.