26 Charles Darwin. 



above the surface, striking an inquisitive observer 

 full in the face. 



Darwin was perhaps the first also to observe 

 that the octopus is luminous at times. One which 

 he kept in his cabin gleamed with a slight phospho- 

 rescence, which we can imagine might be used as a 

 decoy, or perhaps to menace its foes. 



In February, 1831, the Beagle sighted the famous 

 St. Paul's Rocks, one of the most desolate spots on 

 the globe, consisting of a few rocks f\ve hundred 

 and forty miles from the American coast and three 

 hundred and fifty from Fernando de Noronha. The 

 rocks are somewhat difficult to find, as they rear 

 themselves but fifty feet above the sea and are 

 but little over three-quarters of a mile in circum- 

 ference. From a distance they appear white, from 

 the constant presence of vast numbers of birds 

 which have made the location their roosting-place for 

 generations. 



The birds, principally the noddy and tern, were 

 so tame that any number could have been killed by 

 hand. They laid their eggs on the rocks where the 

 sun hatched the young. Desolate as the spot was, 

 warfare existed ; the parent birds provided the 

 young with small fish for food, the flying-fish being 

 considered an especial dainty ; but no sooner was 

 it placed by the nest than the young naturalist, 

 who was concealed behind some rock, saw a hand- 

 somely mottled crab — the Grapsus — come slowly 

 up, edging along in an innocent, disinterested fashion, 

 then suddenly when within reach seize the fish and 

 dash away. 



