Page:Aspects of nature in different lands and different climates; with scientific elucidations (IA b29329668 0002).pdf/81

 *[Footnote: "En appelant l'attention des naturalistes sur les animalcules des coraux, nous espérons démontrer que tout ce qu'on a dit ou cru observer jusqu'à ce jour relativement aux immenses travaux qu'il sont susceptibles d'exécuter, est le plus souvent inexact et toujours excessivement exagéré. Nous pensons que les coraux, loin d'élever des profondeurs de l'océan des murs perpendiculaires, ne forment que des couches ou des encroûtemens de quelques toises d'èpaisseur." Quoy and Gaimard also propounded (p. 289) the conjecture that the Atolls, (coral walls enclosing a lagoon), probably owed their origin to submarine volcanic craters. Their estimate of the depth below the surface of the sea at which the animals which form the coral reefs (the species of Astræa, for example) could live, was doubtless too small, being at the utmost from 25 to 30 feet (26-1/2 to 32 E.) An investigator and lover of nature who has added to his own many and valuable observations a comparison with those of others in all parts of the globe, Charles Darwin, places with greater certainty the depth of the region of living corals at 20 to 30 fathoms. (Darwin, Journal, 1845, p. 467; and the same writer's Structure of Coral Reefs, p. 84-87; and Sir Robert Schomburgk, Hist. of Barbadoes, 1848, p. 636.) This is also the depth at which Professor Edward Forbes found the greatest number of corals in the Egean Sea: it is his "fourth region" of marine animals in his very ingenious memoir on the "Provinces of Depth" and the geographical distribution of Mollusca at vertical distances from the surface. (Report on Ægean Invertebrata in the Report of the 13th Meeting of the British Association, held at Cork in 1843, pp. 151 and 161.) The depths at which corals]*