332 APPENDIX. 



higlier; sea-shells, fragments of coral, sea-hedge- 

 hog shells, and their broken oft' prickles are united 

 by the burning sun, through the medium of the 

 cementing calcareous sand, which has arisen from 

 the pulverisation of the above-mentioned shells, 

 into one whole, or solid stone, which, strengthened 

 by the continual throwing up of new materials, 

 gradually increases in thickness, till it at last be- 

 comes so high, that it is covered only during some 

 seasons of the year by the high tides. The heat 

 of the sun so penetrates the mass of stone when 

 it is dry, that it splits in many places, and breaks 

 off" in flakes. These flakes, so separated, are raised 

 one upon another by the waves at the time of high 

 water. The always active surf throws blocks of 

 coral (frequently of a fathom in length, and three 

 or four feet thick) and shells of marine animals 

 between and upon the foundation stones ; after 

 this the calcareous sand lies undisturbed, and offers 

 to the seeds of trees and plants cast upon it by 

 the waves, a soil upon which they rapidly grow 

 to overshadow its dazzling white surface. Entire 

 trunks of trees, which are carried by the rivers 

 from other countries and islands, find here, at 

 length, a resting place, after their long wanderings : 

 with these, come some small animals, such as lizards 

 and insects, as the first inhabitants. Even before 

 the trees form a wood, the real sea-birds nestle 

 here ; strayed land-birds take refuge in the bushes ; 

 and at a much later period, when the work has 



\3 



