40 SUPPLEMENT ON 



winds convey it along with the current towards the north 

 point of South America, whence a part is drawn into the 

 Caribbean Sea, and Gulf of Mexico ; after sweeping round 

 these shores, it escapes again by the straits of the Gulf of 

 Florida in a north-eastern direction with the stream, till the 

 north-westerly winds and the arctic currents conjointly carry 

 the weed eastward towards the Azores, from whence tropical 

 evaporation draws it again southward to recommence the 

 same gyration l . There is a similarly revolving current 

 south of the equator, bearing the same kind of marine 

 vegetation, and its concomitant inhabitants, but much more 

 scattered, and reverting only in part towards the Cape of 

 Good Hope, while the rest may reach entirely across the 

 Indian Ocean, float alternately in the direction of the mon- 

 soons, or passing up the straits of the great islands of south- 

 ern Asia, ascend till it congregates in the Japan Seas, where 

 it has been observed to be particularly abundant. The Pa- 

 cific has besides a great variety of other vegetable substances 

 floating with the winds and currents ; and beneath the equa- 

 torial line, in the region of frequent calms, vast streaks of 

 peculiar colours often occupy spaces of more than a degree 

 in longitude, indicating the surface of the sea to be covered 

 with fish-spawn, and with infinite multitudes of medusae and 

 other free acalephas, who have in those latitudes the centre 

 of their existence. It may perhaps be worth remarking, that 



1 Doctor Leach in MSS. enumerates several genera of malacostraca, 

 &.c. which Mr. Cranch took from these plants. Some of them are now 

 published in the transactions of the Plymouth Society. I have myself 

 found among other species an albula (Plumieri ?) and small serrani in the 

 fucus natans off Trinidad. It was no doubt an immense field of the weed 

 which impeded the progress of the Carthaginians on their expedition of 

 discovery along the west coast of Africa, and the same plant also caused 

 great uneasiness to the crews of Columbus's ships. C. H. S. 



