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 1 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, “ C’est 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, 
1 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. 
