Hydrography.^ and the Art of Ncuvi^ution. 55 



nion that there are, in these latitudes, numerous banks in the 

 bottom of the ocean on which the fuci grow, and from which 

 they are accidentally detached ; others, that these plants vege- 

 tate, and develope themselves even on the surface of the water ; 

 but the opinion most generally received is, that the Sea of Weeds 

 is the place where the Gulf-Stream continually deposits the plants 

 with which it becomes charged on issuing from the Gulf of 

 Mexico. 



This last mentioned hypothesis has been adopted by Major 

 Rennel, although it is very far from explaining why a great 

 proportion of the floating weeds in the sea of Sargasso are, in- 

 stead of being faded or decayed, in a state of great freshness. 

 Indeed, English navigators never fail, when they speak of these 

 regions, to mention the Jresh weed^ and weed much decayed* 

 Christopher Columbus himself, as M. de Humboldt has remark- 

 ed, was likewise struck with the mixture of yerba muy vieja y 

 otra muyjresca. 



The floating fuci of the sea of Sargasso are always destitute 

 of roots and fruit. If we suppose them to be developed in the 

 same region where they are found, we must regard them, as M. 

 Meyer has done, as similar to fresh- water algae,' many of which 

 multiply only by new branches. It will likewise remain to be 

 explained by what means it is that the waters over such a great 

 extent of sea escape so completely from the action of winds and 

 currents, that the lapse of several ages has not dispersed the 

 plants which were found collected there in the end of the fif- 

 teenth century, when the galleys of Columbus ploughed it for 

 the first time. 



It doubtless appears more natural to suppose, that, as the 

 winds and currents by degrees draw the floating fuci beyond 

 the ordinary limits of die Sea of Plants, their place at the sur- 

 face is occupied by others detached from the bottom. Accord- 

 ing to this hypothesis the plants are stationary only in appear- 

 ance ; the sea will always appear equally covered above the 

 region which nourishes them, but the indi\ddual8: will be con- 

 tinually renewed. 



What, then, is necessary at the present time to throw ligliton 

 this curious point of physics ? A few very simple experiments, 

 which,, however,, are still wannn:^ to science : Soundings made 



