268 THE OCEAN. 
ness, a3 all who have seen it testify, its structure, 
on examination, is found to be no less interesting 
and wonderful. The beach of white sand, which 
opposes the whole force of the Ocean, is found to 
be the summit of a rock which rises abruptly from 
an unknown depth, like a perpendicular wall. The 
whole of this rampart, as far as our senses can 
take cognizance of it, is composed of living coral, 
and the same substance forms the foundation of the 
curved and more elevated side which is smiling in 
the luxuriance and beauty of tropical vegetation. 
The elevation of the coral to the surface is not 
always abruptly perpendicular; sometimes reefs of 
varying depths extend to a considerable distance 
in the form of successive platforms or terraces. In 
these regions may be seen islands in every stage 
of their formation: “some presenting little more 
than a point or summit of a branching coralline 
pyramid, at a depth scarcely discernible through the 
transparent waters; others spreading, like submarine 
gardens or shrubberies, beneath the surface; or 
presenting here and there a little bank of broken 
coral and sand, over which the rolling wave occa- 
sionally breaks;” while others exist in the more 
advanced state that I have just described, the main 
bank sufficiently elevated to be permanently pro- 
tected from the waves, and already clothed with 
verdure, and the lagoon enclosed by the narrow 
bulwark of the coral reef. Though the rampart thus 
reared is sufficient to preserve the inner waters in 
a peaceful and mirror-like calmness, it must not 
be supposed that all access to them from the sea 
