Narrative of the surveying voyages of his majesty's ships Adventure and Beagle (vol.2): between the years 1826 and 1836 : describing their examination of the southern shores of South America, and the Beagles's circumnavigation of the globe

1836. ANIMALS — FRKSH WATER. 635 As if in speaking of these singular, though so small islands, — where crabs eat cocoa-nuts, fish eat coral, dogs catch fish, men ride on turtle, and shells are dangerous man-traps,* any thing more were necessary to ensure the voyager''s being treated like the old woman's son who talked to her about flying-fish, — it must yet be said that the greater part of the sea-fowl roost on branches, and that many rats make their nests at the top of high palm-trees. Except sea-fowl and the domestic creatures-]- which have accompanied man to the Keelings, there is no bird or animal but a kind of land-rail, which is numerous. Besides the palm there are upon the largest islets other trees, particu- larly a kind of teak, and some less valuable wood, from which a vessel was built. Fresh water is not scarce on the larger islets of the group, but it is only to be got by digging wells in the coral founda- tion, covered as it is by vegetation. In these wells, about six feet deep, the water rises and falls as the tide of the ocean flows and ebbs ; which I believe to be the case at most other coral islands where there is fresh water. It appears that the fresh water of heavy rains is held in the loose soil, (a mixture of coral, sand, and decayed vegetable substances,) and does not mix with the salt water which surrounds it, except at the edges of the land. The flowing tide pushes on every side, the mixed soil being very porous, and causes the fresh water to rise : when the tide falls the fresh water sinks also, A sponge full of fresh water placed gently in a basin of salt water, will not part with its contents for a length of time if left untouched. The water in the middle of the sponge will be found untainted by salt for many days ; perhaps much longer, if tried. A word about the inhabitants, and I leave the Keelings. No material diffei'ence was detected by me between the Malays on these islands, and the natives of Otaheite or New Zealand. I do not mean to assert that there were not numbers of men • Chama gigantea. There is a larg;e one in the United Service Museum. t Rats and mice included ; which swarm on those islands.