1S50*.] Linnean Society. 77 



therarum lobi confluentes et inde 4-locellati, rima transversali v. vei'- 

 ticali bivalvatim hiantes. 



Perianthii lacinitfi 4. Stamina 2 3. Soridiutn. 



Perianthii lacinise 6. Stamina 6 4. Sciaphila. 



Perianthii lacinise 8. Stamina 4 5. Hyalisma. 



May 7. 

 R. Brown, Esq., President, in the Chair. 



M. Alphonse DeCandolle, and Asa Gray, M.D., were elected 

 Foreign Members. 



The President exhibited a leaf of the Victoria Water-lily, ob- 

 tained by him from the stove of the Duke of Northumberland at 

 Syon Park, where the plant is now flowering freely, and made some 

 observations on the characters and affinity of the genus. 



Read a letter, dated May 19, 1845, addressed by the President to 

 Admiral Sir Francis Beaufort, for communication to Baron Alexander 

 von Humboldt, " On the Origin and Mode of Propagation of the 

 Gulf- weed." The letter is as follows : — 



" My dear Captain Beaufort, 

 " I am vexed to have kept Baron Humboldt's letter so long, and 

 now in returning it, that it should be accompanied by so little satis- 

 factory information on the only one of jts queries with which I could 

 have been supposed to deal, namely that which relates to the origin 

 and mode of propagation of the Gulf- weed. 



" On this subject it appears that M. de Humboldt (in his Personal 

 Narrative) first supported the more ancient notion, that the plant, 

 originally fixed, was brought with the stream from the Gulf of 

 Florida, and deposited in what Major Rennell calls the recipient of 

 that stream. More recently, however. Baron Humboldt has adopted 

 the opinion*, also held by several travellers, that the Gulf-weed 

 originates and propagates itself where it is now found. To the 

 adoption of this view it appears that he has been led chiefly by the 

 observations of the late Dr. Meyen, who in the year 1830 passed 

 through a considerable portion of the great band of Gulf- weed, and 



* Histoire de la Geographie du Nouveau Continent, vol. iii. p. 7.3, and 

 Meyen, Reise, vol. i. p. 36-9. 



