14 Cruise of the "Alert." 



on the water close to our stern, in flocks of twelve or fourteen, 

 and feeding greedily on the rubbish thrown overboard. It seems 

 that the natural food of these birds (which probably consists of 

 the minute surface organisms) is not within their reach when the 

 surface of the water is unbroken, and hence during calms they 

 are more than commonly anxious to avail themselves of any offal 

 thrown overboard. It was most interesting to observe the neat and 

 graceful way in which they plant their webbed feet on the water, as 

 with outstretched wings and legs erect they maintain a stationary 

 attitude while pecking at the object of their fancy. They appeared 

 to scrupulously avoid wetting the tarsi, and still to use the feet 

 as a means of maintaining a fixed position on the surface of the 

 water. I had never previously observed those untiring little navi- 

 gators at rest in mid-ocean, but on this occasion we all saw them, 

 with wings closed, floating as placidly on the water as ducks in a 

 millpond. The old idea of their following ships only before and 

 during stormy weather is, I believe, now quite exploded. I think 

 that within the tropics, at all events, they are most numerous in 

 the vicinity of ships during calm weather. Finding animal life 

 scarce at the surface, I tried the tow-net sunk to a depth of about 

 three fathoms, and having previously raked the surface, was enabled 

 to institute a comparison ; the result being that similar species 

 were captured in both situations, but that a far greater number 

 of individuals were present in the deeper water. During the day- 

 time we obtained a number of Crustaceans, several Atlanta shells, 

 Globigerina bulloides^ and the same conferva as on the previous 

 day. After dark I got a great quantity of highly phosphorescent 

 Crustaceans, and one small cuttle-fish. 



On the 20th the trade wind returned in full force, and the 

 monotony of an otherwise uneventful day was varied by the 

 appearance of a shoal of porpoises, which accompanied us for 

 some time, moving along abreast of us and about two hundred 

 yards off on our starboard beam, and making themselves con- 

 spicuous by their usual frisky behaviour. 



