$& KEELING ISLAND. [CHAP. xx. 



One day, however, by merely touching my face with ofle of the branches, 

 pain was instantaneously caused; it increased as usual after a few 

 seconds, and remaining sharp for some minutes, was perceptible for 

 half an hour afterwards. The sensation was as bad as that from a 

 nettle, but more like that caused by the Physalia or Portuguese man- 

 of-war. Little red spots were produced on the tender skin of the arm, 

 which appeared as if they would have formed watery pustules, but did 

 not. M. Quoy mentions this case of the Millepora ; and I have heard of 

 stinging corals in the West Indies. Many marine animals seem to have 

 this power of stinging : besides the Portuguese man-of-war, many jelly- 

 fish, and the Aplysia or sea-slug of the Cape de Verd Islands, it is 

 stated in the voyage of the Astrolabe, that an Actinia or sea-anemone, 

 as well as a flexible coralline allied to Sertularia, both possess this 

 means of offence or defence. In the East Indian sea, a stinging sea- 

 weed is said to be found. 



Two species of fish, of the genus Scarus, which are comr-sn here, 

 exclusively feed on coral : both are coloured of a splendid bluish-green, 

 one living invariably in the lagoon, and the other amongst the outer 

 breakers. Mr. Liesk assured us, that he had repeatedly seen whole 

 shoals grazing with their strong bony jaws on the tops of the coral 

 branches : I opened the intestines of several, and tound them distended 

 with yellowish calcareous sandy mud. The slimy disgusting Holuthurise 

 (allied to our star-fish), which the Chinese gourmands are so fond of, 

 also feed largely, as I am informed by Dr. Allan, on corals ; and the 

 bony apparatus within their bodies seems well adapted for this end. 

 These holuthuriae, the fish, the numerous burrowing shells, and nereidous 

 worms, which perforate every block of dead coral, must be very efficient 

 agents in producing the fine white mud which lies at the bottom and on 

 the shores of the lagoon. A portion, however, of this mud, which when 

 wet strikingly resembled pounded chalk, was found by Professor 

 Ehrenberg to be partly composed of siliceous-shielded infusoria. 



April I2th. In the morning we stood out of the lagoon on our 

 passage to the Isle of France. I am glad we have visited these islands ; 

 such formations surely rank high amongst the wonderful objects of this 

 world. Captain Fitz Roy found no bottom with a line 7,200 feet in 

 length, at the distance of only 2,200 yards from the shore ; hence this 

 island forms a lofty submarine mountain, with sides steeper even than 

 those of the most abrupt volcanic cone. The saucer-shaped summit is 

 nearly ten miles across; and every single atom,* from the least particle 

 to the largest fragment of rock, in this great pile, which however is 

 small compared with very many other lagoon-islands, bears the stamp 

 of having been subjected to ^gamc arrangement. We feel surprise 

 when travellers tell us of ,.e vast dimensions of the Pyramids and 

 other great ruins, but how utterly insignificant are the greatest of these, 

 when compared to these mountains of stone accumulated by the agency 



* I exclude, of course, some soil which has been imported here in vessels 

 from Malacca and Java, and likewise some small fragments of pumice, drifted 

 bere by the waves. The one block of green-stone, moreover, on the 

 oorthern island must be excepted. 



