186 A NATURALIST ON DESERT ISLANDS. 



evolution comparable to that of Blanquilla, when the 

 coral platform noted above had just emerged above the 

 surrounding sea. 



At this time we can picture this long and low reef 

 covered with the first vegetable immigrants to gain a 

 footing on it, and inhabited by a teeming population of 

 flamingoes, boobies, pelicans, frigate-birds, terns, and 

 shore-birds, while no doubt vast numbers of turtles 

 would have resorted to it to lay their eggs. 



How interesting, therefore, it would be, if we are correct, 

 to compile an exact inventory of the flora of this belt of 

 trees which now grows on the old upraised reef, and to 

 compare it with that of the West Indian islands and the 

 mainland adjoining. The ancestors of everything grow- 

 ing on it must have been originally transported by means 

 of ocean currents, winds or birds. We seem to see these 

 vegetable invaders drawn up along the windward side of 

 the island like the long lines of an invading army. They 

 have effected a landing, and have seized upon the only 

 strip of coral territory which could afford them support. 

 They have extended their operation to the very uttermost 

 limits of this territory and then have stopped short, 

 suddenly brought up by the question of " supply," and 

 utterly non-plussed at the harsh, hungry and bare gneiss 

 facing them beyond, and which said in effect, " Thus 

 far shalt thou come and no further." 



Like the Danes, who invaded our own eastern shores in 

 days gone by, these vegetable invaders have arrived 

 from over the sea ; like the Danes they have swooped 

 down upon everything they could lay their hands on ; 

 but like them, too, they have never been able to push 

 their advantage beyond a certain distance inland. Which 

 of all the many forms of West Indian vegetation have 

 been able to gain a footing here, and havmg gained it 

 have been able to keep it ? 



