514 MR. J. J. LISTER ON THE NATURAL [DcC. 4, 



I believe that these terraces, though in a general way continuous 

 round the island, except at the headlands, do not correspond at 

 different places terrace for terrace. 



It was not easy to settle this question, as the slopes were all covered 

 with trees, and travelling over the sides of the island was most 

 difficult. 



I once, however, had a good opportunity of forming an opinion 

 on the matter, on an occasion I shall long remember. I had started 

 about sunrise from the ship in Plying-Fish Cove to go to the western 

 landing. It was a deliciously fresh morning, and as we sped along 

 over the blue water a school of porpoises came plunging alongside 

 of us, while overhead a flock of Frigate-birds, Gannets, and Boobies 

 kept us company, the last often flying so near that the men hit 

 at them with boathooks. As the sun rose over the island the light 

 struck obliquely along the northern side, lighting up the trees on 

 the terraces while the steep slopes were still in shadow. I then saw 

 that the lines of shadow, though in the main horizontal, frequently 

 broke up and joined with one another, showing, as I believe, that the 

 individual terraces are not continuous at the same level on the sides 

 of the island. 



At the headlands the higher part of the island generally terminates 

 in a sheer cliff, from the foot of which a gradual slope extends to the 

 sea. This inland cliff and the slope below it are repeated again and 

 again in the contours of the projecting headlands as they are seen 

 looking along the shore. The low foot of rock extends almost all 

 round the island and ends in a shore-cliff, which varies in height from 

 15 to nearly 60 feet. It has an abrupt vertical face and is much 

 underworn by the waves and traversed by fissures which penetrate 

 far into the rock and in some places give rise to blowholes from which 

 columns of spray shoot up at intervals from among the green bushes 

 which cover the surface. 



This shore-cliff is obviously made of coral, but the structure has 

 begun to be obliterated by the deposit of lime in the interstices. 

 This was most clearly seen in one place where some large oval boulders 

 of coral, one of which measured 7 ft. 3 in. in transverse circum- 

 ference, had been tossed up to the top of the shore-cliff (here about 

 15 feet from the mean sea-level) and had worn out hollows in the 

 rock. The contrast between the clearly defined structure of the 

 boulders and the partly obliterated characters of the coral which 

 formed the cliffs shows that the change is here in progress which 

 has converted the reefs of the upper terraces into a compact hard 

 rock in which very little sign of their origin is visible. 



In many places deep water extends up to the cliffs. At the western 

 landing-place and at Flying- Fish Cove was a beach of rolled fragments 

 and shells, then a narrow flat strip of dead coral strewn with lumps 

 carried by the waves, beyond this a narrow line of growing coral- 

 reef sloping down rapidly to deep water, on which as we approached 

 the shore the beds of hving coral could be seen, separated by tracts 

 of white sand. 



