190 Transactions. — Zoology, 



3rd February. — z\bout 10 o'clock this morning I saw a 

 large Petrel, dark-grey on the upper and white on the under 

 surface, which followed in our wake for an hour or more with 

 a very hawk-like flight. After this, not a wing of any sort nor 

 other sign of animal life till night, when the sea was ablaze 

 with phosphoric displays — sparks and flashes of light — given 

 out, no doubt, by Medusae and other small invertebrate in- 

 habitants of the deep ; but, in addition to this, the whole of 

 the disturbed v/ater seemed luminous, the effect being probably 

 due to the decomposition of animal matter on the surface of the 

 ocean. There had been a breeze from the E.N.E. all day, it 

 was misty in the afternoon, and there was nothing in the way 

 of a sunset. The night was dark, and these phosphorescent 

 effects were very beautiful. Jupiter was resplendent in the 

 heavens, and Sirius shone with his accustomed pale efful- 

 gence ; but the sparkling lights on the surface of the water as 

 our steamer ploughed her way through it seemed more bril- 

 liant even than those of the firmament above : everywhere 

 points of light that flashed like sparks from a giant dynamo 

 and expired in a tiny illumination, and occasional balls of 

 lambent flame which dashed past the ship and then dissolved 

 in an instant in the seething foam, reminding one of Coleridge's 

 graphic, although perhaps rather overdrawn, description : " A 

 beautiful white cloud of foam at momently intervals coursed 

 by the side of the vessel with a roar, and little stars of flame 

 danced and sparkled and went out in it ; and every now and 

 then light detachments of this white cloud-like foam darted off 

 from the vessel's side, each with its own small constellation, 

 over the sea, and scoured out of sight like a Tartar troop over 

 a wilderness." Darwin writes in " The Voyage of the ' Beagle 

 (ed. 1893, p. 154), " While sailing a little south of the Plata on 

 one very dark night, the sea presented a wonderful and very 

 beautiful spectacle. There was a fresh breeze, and every part 

 of the surface, which during the day is seen as foam, now 

 glowed with a pale light. The vessel drove before her bows 

 two billows of liquid phosphorus, and in her wake she was 

 followed by a milky train. As far as the eye reached the crest 

 of every wave was bright, and the sky above the horizon, from 

 the reflected glare of these lurid flames, was not so utterly 

 obscure as over the vault of the heavens." Later on, in 

 discussing this phenomenon, he says, "I am inclined to con- 

 sider that the phosphorescence is the result of the decomposi- 

 tion of the organic particles, by which process (one is tempted 

 almost to call it a kind of respiration) the ocean becomes puri- 

 fied." Although now about a hundred miles from the African 

 coast, a quantity of impalpable red dust was deposited to-day 

 on the ship, all the rigging being more or less tinted with it. 

 It is no doubt composed of minute Infusoria, instances of the 



