182 A NATURALIST ON DESERT ISLANDS. 



our iron-shod feet like metal. Every here and there, one 

 came across small areas and pockets of good-looking soil ; 

 but for the most part the bare rock was either jagged and 

 rough, making an abominable surface to walk on, or was 

 as flat and smooth as a pavement. Yet trees, bushes, 

 and even flowering plants, flourished on it to an extent 

 out of all proportion to those found anywhere else on the 

 island. 



These smooth level surfaces of coral limestone, exhibited 

 everywhere an obvious organic structure, with perfectly 

 distinct remnants of the original reef builders ; so that it 

 was quite evident that we were walking on a comparatively 

 very recently upraised coral f ringing-reef . This reef, as 

 far as we had time to trace it, stretches as a dead level 

 platform, at an elevation of about two hundred feet above 

 the sea, and is of a varying breadth of a mile or less. 

 It extends all along the eastern (windward) side of 

 the island ; but towards its southern border, it ceases 

 abruptly within about half a mile from the sea, between 

 which and the edge of the platform, the ground slopes 

 rapidly down, and is occupied by an undulating surface of 

 much-weathered granite, covered with a thick growth of 

 cactus of several varieties (Cereus, Echinocactus, Melo- 

 cactus, Opuntias, etc.) 



Some of the trees which we noticed growing on this 

 platform of coral were of quite respectable growth, attain- 

 ing to a height of sixty feet or more ; but for the most part, 

 it was covered with a thick bushy growth of acacias and 

 guaiacum. As far as we could judge, without any means 

 of forming anything but a guess, the height of the reef 

 above the sea must be nearly two hundred feet, that is 

 to say, practically the same height as the central plateau, 

 which again is the highest part of the island. 



A glance at the accompanying plan of the island, 

 enlarged from a chart and slightly corrected according 

 to the findings of the yacht's officers, will give the reader 

 a rough idea of the situation and extent of this capping of 

 coral formation, and its relation to the rest of the granite 



