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had been cultivated with great success. Mr. Lawson presented the 

 specimen to the museum at the Botanic Garden. 

 The following papers were read : — 



1. * On the Gulf- weed [Sargassum hacciferum) ;' by Samuel Moss- 

 man, Esq. The Sea of Sargasso may be considered as an eddy, situ- 

 ate in point of latitude between the regular equinoctial current on the 

 south, setting to the westward, the south-easterly current from the 

 northern sea on the east, and as the recipient of the gulf stream from 

 the north and north-west. The tract which is occupied is more than 

 1200 miles in length from north to south, and within these limits the 

 weed appears in greater quantities than elsewhere ; and it does not 

 appear to have varied its position in any degree during the last fifty 

 years. Hence it appears to have been stationary for ages ; perhaps 

 from the time of Columbus, by whom it was first noticed. Major 

 Rennell observes that the breadth of this mass of weed is small in 

 proportion to its length, being drawn out into a kind of stream, and 

 bending a little to the east of south. Dr. Franklin crossed it in lat. 

 36 deg. I Tnin., and found it less than fifty miles in breadth ; but it 

 spreads to the southward, and in lat. 20 deg. appears to have been, at 

 times, 150 miles wide, although, perhaps, consisting only of various 

 parallel streams of weed. It has been observed that the waters of the 

 Atlantic have a greater tendency towards the middle of the ocean 

 than otherwise ; and this seems to indicate a reduced level, forming a 

 kind of hollow space or depressed surface. It is certain that the set- 

 ting of the currents is such as might be expected to take place if such 

 a hollow existed ; for the currents do really set into the Sargasso Sea 

 from the north and the south, whilst in the middle part, although 

 within the region of the trade-wind, the currents are not regular, but 

 indicate a kind of vortex. From the great central mass portions of 

 the weed appear to be carried by the drift to the south-west, towards 

 the Virgin Isles, Porto Rico, &c., until they fall into the great equato- 

 rial current. Mr. Mossman entered at considerable length upon the 

 much-disputed question of the origin and mode of growth of Sargas- 

 sum, and detailed the opinions of the various botanists and travellers 

 who had written on the subject. He remarked that there was a great 

 want of observations on this subject by really scientific botanists, as 

 many facts bearing on the question rest solely on the authority of 

 travellers unacquainted with botany, and therefore not commanding 

 implicit reliance. He concluded by reading a letter addressed by 

 Dr. Robert Brown, President of the Linnean Society, to Admiral Sir 



