583 PROPAGATION OP THE GULl'-WEED. 



between the Gulf-weed and some other Sargassa, especially 

 8. yiatans, are not such as to prove these two species to be 

 pernianentl}' distinct. The most remarkable of these dif- 

 ferences consists in the leaves of the Gulf-weed being 

 uniformly destitute of those dots or areolae so common in 

 the genus Savffassum, and which a\'e constantly present in S. 

 tiatans. These dots, in their greatest degree of development, 

 bear a striking resemblance to the perforations or apertures 

 of the imbedded fructification in the genus. But as the 

 receptacles of the fructification, as well as the vesicles, are 

 manifestly metamorphosed leaves ; and as the production of 

 fructification is not adapted to the circumstances in which 

 the Gulf- weed is placed, it is not wholly improbable, though 

 this must be regarded as mere hypothesis, that the propa- 

 gation by lateral branches, continued for ages, may be 

 attended with the entire suppression of these dots. 



" That the Gulf-weed of the great band is propagated 

 80] solely by lateral or axillary ramification, and that in this 

 way it may have extended over the immense space it now 

 occupies, is highly probable, and perhaps may be affirmed 

 absolutely without involving the question of origin, which 

 I consider as still doubtful. 



" My conclusion, therefore, is somewhat different from that 

 of Baron Humboldt, to whom 1 would beg of you to forward 

 these observations, which will prove that 1 have not been 

 inattentive to his wishes and to your own, though they will 

 at the same time prove that I have had very little original 

 information to communicate." 



