CHAP. I.] BERMUDAS TO MADEIRA. 15 



was examined by Mr. Buchanan, and found to contain, like the 

 nodules dredged in 2435 fathoms at Station XVI., 700 miles to 

 the east of Sombrero, a large percentage of peroxide of manga- 

 nese. Some other concretionary lumps were of a gray color, 

 but all of them contained a certain proportion of manganese, 

 and they seemed to be gradually changing into nodules of py- 

 rolusite or wad by some process of infiltration or substitution. 



On Wednesday, June 18th, we resumed our course with a 

 fine breeze, force 5 to 7, from the south-east. In this part of 

 our voyage we were again greatly struck with the absence of 

 the higher forms of animal life. Not a sea-bird was to be seen, 

 with the exception of a little flock of Mother Carey's chickens, 

 here apparently always Thalassidroma Wilsoni, which kept 

 playing round the ship on the watch for food, every now and 

 then concentrating upon some peculiarly rich store of offal as it 

 passed astern, and staying by it while the ship went on for a 

 quarter of a mile, fluttering above the water and daintily touch- 

 ing it with their feet as they stooped and picked up the float- 

 ing crumbs, and then rising and scattering in the air to over- 

 take US and resume their watch. 



The sea itself in the bright weather, usually under a light 

 breeze, was singularly beautiful — of a splendid indigo-blue of 

 varying shades as it passed from sunlight into shadow, flecked 

 with curling white crests ; but it was very solitaiy : day after 

 day went by without a single creature — shark, porpoise, dol- 

 phin, or turtle — being visible. Some gulf -weed passed from 

 time to time, and bunches of a species of Fiicus, either F. nodo- 

 sus or a very nearly allied form, evidently living and growing, 

 and participating in the wandering and pelagic habits of Sa?'- 

 gassurii. The floating islands of the gulf-weed, with which we 

 had become very familiar, as we had now nearl}^ made the cir- 

 cuit of the " Sargasso Sea," are usually from a couple of feet 

 to two or three yards in diameter, sometimes much larger : we 

 have seen, on one or two occasions, fields several acres in ex- 



