466 LAGOON-ISLANDS, [cutar. xx. 
de Laval well exclaimed, “‘C’est une meruille de voir chacun 
de ces atollons, enuironné d’un grand banc de 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 ina 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 pro- 
tection in the inner parts; but so far is this from the truth, that 
those massive kinds, to whose growth on the exposed outer shores. 
the very existence of the reef depends, cannot live within the 
lagoon, where other delicately-branching kinds flourish. More- 
over, on this view, many species of distinct genera and families 
are supposed to combine for one end; and of such a combination, 
not a single instance can be found in the whole of nature. The 
theory that has been most generally received is, that atolls are 
based on submarine craters; but when we consider the form and 
size of some, the number, proximity, and relative positions of 
others, this idea loses its plausible character: thus, Suadiva atoll 
is 44 geographical miles in diameter in one line, by 34 miles in 
another line; Rimsky is 54 by 20 miles across, and it has a 
strangely sinuous margin ; Bow atoll is 30 miles long, and on an 
average only 6 in width; Menchicoff atoll consists of three atolls 
united or tied together. This theory, moreover, is totally inap- 
