Jan. 

 1326 



182 VOYAGE TO THE 



c ^ p - of lime, calcareous spar, crystals, an alcime, olivine, 

 jasper, and chalcedony ; and had our stay, and his 

 other duties admitted, we should, no doubt, have 

 received from him a more detailed account of this 

 interesting groupe. 



There are no appearances of pseudo-craters on any 

 of the islands, nor do they seem to have been very 

 recently subjected to fire, being clothed with ver- 

 dure, and for the most part with trees. Conspicu- 

 ously opposed to these lofty rugged formations, 

 raised by the agency of fire, is a series of low islands, 

 derived from the opposite element, and owing their 

 construction to myriads of minute lithophytes en- 

 dowed with an instinct that enables them to sepa- 

 rate the necessary calcareous matter from the ocean, 

 and with such minute particles to rear a splendid 

 structure many leagues in circumference. A great 

 wall of this kind, if we may use the expression, 

 already surrounds the islands, and, by the unremit- 

 ting labour of these submarine animals, is fast ap- 

 proaching the surface of the water in all its parts. 

 On the N. E. side, it already bears a fertile soil be- 

 yond the reach of the sea, sustains trees and other 

 subjects of the vegetable kingdom, and affords even 

 an habitation to man. 



In the opposite direction it dips from thirty to 

 forty feet beneath the surface, as if purposely to 

 afford access to shipping to the lagoon within. 

 Whether this irregularity be the consequence of 

 unequal growth, or of the original inclination of 

 the foundation, is a question that has excited much 

 interest. All the islands we subsequently visited 

 were similar to these in having their weather or 

 eastern side more advanced than the opposite one. 



