580 ON THE ORIGIN ANB MODE OE 



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

 passed through a considerable portion of the great band of 

 7n] Gulf-weed, and who ascertained, as he states, from the 

 examination of several thousand specimens, that it was 

 uniformly destitute both of root and fructification ; he con- 

 cludes, therefore, that the plant propagates itself solely by 

 lateral branches ; he at the same tune denies that it is 

 brought from the Gulf of Florida, as, according'^to his own 

 observation, it hardly exists in that part of the stream near 

 the great band, though found in extensive masses to the 

 westward. I have here to remark that, as far as relates to 

 the absence of root and fructification, Meyen has only con- 

 firmed by actual observation what had been previously stated 

 by several authors, particularly by Mr. Turner (in his ' His- 

 toria Fucorum,' vol. i, p. 103, published in 1808), and 

 Agardh (in his ' Species Algarum," p. 6, published in 1820). 

 But Meyen materially weakens his own argument in stating 

 that he considers the Gulf-weed {8argassum baccifermn of 

 Turner and Agardh), and the Saryassum natans, or vulgare, 

 specifically distinguished from it by these authors, as one 

 and the same species ; adding, that he has observed among 

 the Gulf-weed all the varieties of Sargassum vulgare described 

 by Agardh ; and finally, that on the coast of Brazil he has 

 found what he regards as the Gulf-weed in fructification. 

 Now, as Sargassum natanshas been found fixed by a discoid 

 base or root, in the same manner as the other species of the 

 genus, and as according to Meyen the Gulf-weed has been 

 found in fructification, the legitimate conclusion from his 

 statements seems to be, that this plant is merely modified 

 by the peculiar circumstances in which it has so long been 

 placed. I am not, however, disposed to adopt Dr. Meyen's 

 statement that he actually found the true /Sargassum natans, 

 much less all its supposed varieties, mixed with the Gulf- 

 weed, having reason to believe that at the period of his 

 voyage his practical knowledge of marine submersed Algae 

 was not sufficient to enable him accurately to distinguish 

 species in that tribe. It is not yet known what other species 

 of Sargassum are mixed with the Gulf-weed, what proportion 

 they form of the greai^ band, nor in what state, with respect 



