XX 



LAGOON ISLANDS OR ATOLLS 



495 



to these mountains of stone accumulated by the agency of 

 various minute and tender animals ! This is a wonder which 

 does not at first strike the eye of the body, but, after reflection, 

 the eye of reason. 



I will now give a very brief account of the three great 

 classes of coral-reefs ; namely, Atolls, Barrier and Fringing 

 Reefs, and will explain my views ^ on their formation. Almost 

 every voyager who has crossed the Pacific has expressed his 

 unbounded astonishment at the lagoon islands, or as I shall 

 for the future call them by their Indian name of atolls, and 

 has attempted some explanation. Even as long ago as the 

 year 1605, Pyrard de Laval well exclaimed, " Cast une meruille 

 de voir chacun de ces atollons, enuironne d'un grand banc de 



WHITSUNDAY ISLAND. 



pierre tout autour, n'y ayant point d'artifice humain." The 

 accompanying sketch of Whitsunday Island in the Pacific, 

 copied from Capt. Beechey's admirable Voyage, gives but a 

 faint idea of the singular aspect of an atoll ; it is one of the 

 smallest size, and has its narrow islets united together in a ring. 

 The immensity of the ocean, the fury of the breakers, contrasted 

 with the lowness of the land and the smoothness of the bright 

 green water within the lagoon, can hardly be imagined without 

 having been seen. 



The earlier voyagers fancied that the coral-building animals 

 instinctively built up their great circles to afford themselves 

 protection in the inner parts ; but so far is this from the truth, 



^ These were first read before the Geological -Society in May 1837, and have 

 since been developed in a separate volume on the Structure and Distribution of Coral 

 Reefs. 



