10 ST. Paul's rucks^, 



thus often led me to its discovery. That it possess- 

 es 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 difficvilty which 

 these 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 February 16th, close 

 to the island of St. Paul's. This cluster of rocks is 

 situated in 0° 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 

 I'ises abruptly out of the depths of the ocean. Its 

 mineralogical constitution is not simple : in some 

 parts the rock is of a cherty, in others of a felspath- 

 ic 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 Sey- 

 chelles and this little point of rock, arc, I believe, 

 composed either of coral or of erupted matter. 

 The volcanic nature of these oceanic islands is ev- 

 idently an extension of that law, and the effect of 

 those sam.e causes, whether chemical or mechanical, 

 from which it results that a vast majority of the vol- 

 canoes 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 seafowl, and part- 



