UPRAISED CORAL REEF. 181 



species of acacia (Pithecolobium dulce) forms a distinctive 

 feature in the landscape. Its smooth, oval and rather 

 shiny leaves, which grow in pairs, and its smaU clusters 

 of pale blue flowers render it easy of recognition, if 

 looked for. Its wood, besides being very heavy and not 

 floating in water, is remarkable for exhibiting hardly 

 any trace of annual rings, and for the direction of its 

 fibres, each layer of which crosses the last in a diagonal 

 fashion. There is probably little doubt that its seeds 

 were originally introduced to the island by means of 

 parrots. 



The long belt of woodland, where we found the parrots, 

 and which contains a great number of these guaiacum or 

 lignum vitae trees, forms rather a striking feature of Blan- 

 quiUa ; and the explanation of its existence seems to be 

 worth noting. Seen from the central plateau of the island, 

 it begins as abruptly and is as well defined as if it had been 

 planted by the hand of man, stretching away north and 

 south, along nearly the whole eastern edge of the island, 

 like some long wood or plantation which marks the 

 boundary of a large estate. Except for the small isolated 

 coppices, a few square yards in area, which have been 

 mentioned before as dotting the surface of the high ground 

 in the central parts of Blanquilla, there is not a tree to be 

 seen there ; so that the contrasts between this artificial 

 looking plantation and the arid stretch of barren wilderness 

 had struck us as being most peculiar. 



The peculiarity was all the more marked, since the belt 

 of forest sprang from ground which was on exactly the 

 same level as the rest of the central plateau, with absolutely 

 nothing, as seen from a distance, to mark the existence 

 of any different geological formation, or the presence of 

 any obvious cause favouring the growth of trees. Yet 

 a different formation there proved to be, and one which 

 explained at a glance this curious belt of vegetation : for 

 on entering the wood we passed immediately, almost 

 stepped, in fact, from a granite formation to a nearly 

 bare coral limestone rock, which rang and clinked under 



