6 ST. PAUL'S ROCKS. [CHAP, i, 



This cuttle-fish displayed its chameleon-like power both during the 

 act of swimming and whilst remaining stationary at the bottom. I was 

 much amused by the various arts to escape detection used by one indivi- 

 dual, which seemed fully aware that I was watching it. Remaining for 

 a time motionless, it would then stealthily advance an inch or two, like 

 a cat after a mouse ; sometimes changing its colour : it thus proceeded, 

 till having gained a deeper part, it darted away, leaving a dusky train 

 of ink to hide the hole into which it had crawled. 



While looking for marine animals, with my head about two feet 

 above the rocky shore, I was more than once saluted by a jet of water, 

 accompanied by a slight grating noise. At first I could not think what 

 it was, but afterwards I found out that it was this cuttle-fish, \ which, 

 though concealed in a hole, thus often led me to its discovery. That 

 it possesses the power of ejecting water there is no doubt, and it 

 appeared to me that it could certainly take good aim by directing the 

 tube or siphon on the under side of its body. From the difficulty 

 which tnese animals have in carrying their heads, they cannot crawl 

 with ease when placed on the ground. I observed that one which I 

 kept in the cabin was slightly phosphorescent in the dark. 



ST. PAUL'S ROCKS. In crossing the Atlantic we hove-to, during the 

 morning of the i6th of February, close to the island of St. Paul's. This 

 cluster of rocks is situated in o 58' north latitude, and 29" 15' west 

 longitude. It is 540 miles distant from the coast of America, and 350 

 from the island of Fernando Noronha. The highest point is only fifty 

 feet above the level of the sea, and the entire circumference is under 

 three-quarters of a mile. This small point rises abruptly out of the 

 depths of the ocean. Its mineral ogical constitution is not simple ; in some 

 parts the rock is of a cherty, in others of a felspathic nature, including 

 thin veins of serpentine. It is a remarkable fact, that all the many 

 small islands, lying far from any continent, in the Pacific, Indian, and 

 Atlantic Oceans, with the exception of the Seychelles and this little 

 I -dint of rock, are, I believe, composed either of coral or of erupted matter. 

 The volcanic nature of these oceanic islands is evidently an extension 

 of that law, and the effect of those same causes, whether chemical or 

 mechanical, from which it results \that a vast majority of the volcanoes 

 now in action stand either near sea-coasts or as islands in the midst of 

 the sea. 



The rocks of St. Paul appear from a distance of a brilliantly white 

 colour. This is partly owing to the dung of a vast multitude of sea- 

 fowl, and partly to a coating of a hard glossy substance with a pearly 

 lustre, which is intimately united to the surface of the rocks. This, 

 when examined with a lens, is found to consist of numerous exceedingly 

 thin layers, its total thickness being about the tenth of an inch. It 

 contains much animal matter, and its origin, no doubt, is due to the 

 action of the rain or spray on the birds' dung. Below some small 

 masses of guano at Ascension, and on the Abrolhos Islets, I found 

 certain stalactitic branching bodies, formed apparently in the same 

 manner as the thin white coating on these rocks. The branching bodies 



