DARWIN'S THEORY OF CORAL REEFS.

Samoa Times and South Sea Advertiser, Volume I, Issue 34, 8 June 1889, Page 2

DARWIN'S THEORY OF CORAL REEFS.

According to Mr. Darwin's theory, which has l«en almost universally accepted daring the past half .century, the corals commence to grow close to the shore of an island or continent. As the land slowly sinks the corals meanwhile grow upwards to the surface of the sea, and a water space—the lagoon channel—is formed between the shot© of theisland and the encircling reefc the infringing being thus converted intobarrier reef. Eventually the central island sinks altogether front sight, ami the barrier reef is converted into an atoll, the lagoon marking the place where the volcanic or other lands onee existed. Encircling reefs or atolfs are represented as becoming smaller and smaller us the sinking goes on, and the final stage of the atoll is a small coral islet, less than two mires in diameter, with the lagoon filled up, and covered with deposits of seasalts and guano. It is at onee evident that the views now advocated are in almost all respects the reverse of those demanded by Mr. Darwin's theory. The recent deep-sea investions do sot in any vay suppo t the view that large or small islands once filled the spaces now occupied by the lagoon waters, and that the reefs show approximately the position of the shores of a subsided island. The structure of an upraised coral ; sland so far as yet examined, appears to lend no support to the Darwinian theory of formation. When we remember that the great growing surface of existing reefs is the seaward face from the sea surface down to twenty or forty fathoms, that large quantities of coral debris must be annually removed from lagoons in suspension and solution, that reefs expand laterally and remain always but a few hundred yards in width, that the lagoons of finished atolls are deepest in the centre, and are relatively shallow compared with the depths of the outer radii, then it seems impossible, with oar wMent knowledge, to admit that atolls or barrier reeft have ever been developed after the manner indicated by Mr. Darwin's simple and beautiful theory of coral reeft.—Nature