Sect. I. THE GEOWTII OF COEAL-EEEFS. 85 



cession of breakers ; and living coral nowhere else 

 forms solid, masses. At the Marshall islands the larger 

 kinds of corals (chiefly a species of Astrsea, a genus 

 closely allied to Porites), ' which form rocks measuring 

 several fathoms in thickness,' prefer, according to 

 Chamisso, 1 the most violent surf. I have stated 

 that the outer margin of the Maldiva atolls consists of 

 living corals, (some of which, if not all, are of the same 

 species with those at Keeling atoll), and here the surf is 

 so tremendous, that even large ships have been thrown, 

 by a single heave of the sea, high and dry on the reef, 

 all on board thus escaping with their lives. 



Ehrenberg 2 remarks, that in the Eed Sea the 

 strongest corals live on the outer reefs, and appear to 

 love the surf; he adds, that the more branched kinds 

 abound a little way within, but that these in still 

 more protected places become smaller. Many other 

 facts having a similar tendency might be adduced. 3 It 

 has, however, been doubted by MM. Quoy and Graimard, 

 whether any kind of coral can even withstand, much 

 less flourish in, the breakers of an open sea 4 ; they 

 affirm that the saxigenous lithophytes flourish only 



1 Kotzebue's First Voyage (Eng. Transl.), vol. iii. pp. 142, 143, 331. 



2 Ehrenberg, iiber die Natur und Bildung der Corallen Banke im 

 rothen Meere, p. 49. 



s In the West Indies, as I am. informed by Captain Bird Allen, K.N., 

 it is the common belief of those who are best acquainted with the reefs, 

 that the coral flourishes most where freely exposed to the swell of 'the 

 open sea. 



4 Annales des Sciences Naturelles, torn. vi. pp. 276, 278. — 'Laou 

 les ondes sont agitees, les Lytophytes ne peuvent travailler, parce 

 qu'elles detruiraient leurs fragiles Edifices,' &c. 



