In order to obtain a fresh confirmation or elucidation of this highly important and isolated phenomenon, I addressed myself not long since to my young friend Dr. Joseph Hooker, who, after making the Antarctic voyage with Sir James Ross, has now joined the great Thibeto-Himalayan expedition. Dr. Hooker wrote to me in reply, on his arrival at Alexandria near the end of December 1847, before embarking at Suez: “Our Cœlebogyne still flowers with my father at Kew as well as in the Gardens of the Horticultural Society. It ripens its seeds regularly: I have examined it repeatedly very closely and carefully, and have never been able to discover a penetration of pollen-tubes either in the style or ovarium. In my herbarium the male blossoms are in small catkins.” [5] p. 7.--“_Shine like stars._” The luminosity of the ocean is one of those superb natural phenomena which continue to excite our admiration even when we have seen them recur every night for months. The sea is phosphorescent in every zone; but those who have not witnessed the phenomenon within the tropics, and especially in the Pacific, have only an imperfect idea of the grand and majestic spectacle which it affords. When a man-of-war, impelled by a fresh breeze, cuts the foaming waves, the voyager standing at the ship’s side feels as if he could never be satisfied with gazing on the spectacle which presents itself to his view. Every time that in the rolling of the vessel her side emerges from the water, blue or reddish streams of light appear to dart upwards like flashes of lightning from her keel. Nor can I describe the splendour of the appearance presented on a dark night in the tropic seas by the sports of a troop of porpoises. As they cut through the foaming waves, following each other in long winding lines, one sees their mazy track marked by intense and sparkling light. In the Gulf of Cariaco, between Cumana and the Peninsula of Maniquarez, I have stood for hours enjoying this spectacle. Le Gentil and the elder Forster attributed the flashing to the electric friction excited by the ship in moving through the water, but the present state of our knowledge does not permit us to receive this as a valid explanation. (Joh. Reinh. Forster’s Bemerkungen auf seiner Reise um die Welt, 1783, S. 57; Le Gentil, Voyage dans les Mers de l’Inde, 1779, T. i. p. 685-698.)