36

(62

(Theory of Subsidence)

or circular reefs. The line will thus be 1200 miles long. Now ^{calling to mind} the foundation, on which ^{in these several cases} the lithophytes have constructed, their massive edifices, ^{is either stationary or} has not subsided, it must either have remained stationary or been elevated. On the first of these two latter suppositions, it being allowed that the coral animal, can only flourish at depths, small as compared to the profundity of the ocean, it follows that the submarine mountains, on which, the coral is now growing, reached within such small limits, to the level of the water; and yet that not a single peak rose any higher ^{not formed by small kinds of coral, for time not unlimited?} On the second supposition of a series of elevations, there movements, over the same immense spaces, ceased and never exceeded the limits already pointed out.

[pencil insertion:] Therefore the land cannot have been stationary since or been elevated since corals commenced.

^{There is however alternative suggested by Ehrenberg-} These consequences from the two suppositions, are so improbable (for if otherwise, we might expect to find, in more than one part of the world, great tracts of country, with mountains of a nearly equal height) that to my mind, the evidence of subsidence, ^{putting out of the question form of reefs, their mass of [illeg]} the only remaining supposition is almost demonstratrive ^{possesses a very high probability}. Any direct proof of such movements, excepting in countries, where ancient buildings stand near the sea, can very rarely be discovered.* (a)* On the other hand, proofs of elevation, especially in these coral seas, are most evident, therefore all negative evidence, becomes the more valuable. This subject will however be resumed, when describing the particular groups of islands. I may here add, that Capt Fitz-Roy heard of

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[pencil insertion:] Lyells notes

(a)* It had occurred to me that the discovery of fossil bones of any of the larger mammalia, would throw light upon the existence of a former continent. It was therefore with interest surprise that I read in Mariner's Tonga, an account of some bones celebrated throughout the neighbouring islands as having belonged to an immense giant, which were found on Lotooma, (West of the Navigators). A Tonga chief, who had seen them, told Mr Mariner, he did not think they were human, but supposed they belonged to some fish. It does not appear to me that this latter opinion is of much consequence; it must be recollected that the Tahitians, inhabitants of Wateeoo, when they first saw a sheep, pronounced it to be a bird. There can be no doubt that the islanders must be well acquainted with the bones of the Cetaceæ. These relics, may possibly have belonged to a crocodile; for it appears nearly certain from Mr Mariner's account that one arrived alive on an island belonging to the Feejee group; a distance at least of 1200 miles and probably much more, from its proper habitation. I have referred to these bones, as, if an opportunity should ever occur, it would be well worth while to discover their true nature. Mariner's Tonga. Constable Miscell = Vol: I. P: 260.

Reference:

Mariner, William. 1817. An account of the natives of the Tonga Islands in the South Pacific Ocean. 2 vols. London: printed for the author. vol. 1 Text vol. 2 Text