THE BROWN SEAWEEDS OF THE SALT MARSH. 369 
On the other hand, the forma membranacea of Fucus inflatus, decribed by 
Rosenvinge (1898, p. 46) and in more detail by Jenssen (1904, р. 20), seems 
to be anomalous. It grows in a loose-lying formation off the coasts of 
Greenland ; but it is in full fructification from March to August, and its 
habit is curled and twisted. Fucus inflatus is characteristic of the lowest 
levels of the littoral region; this interesting form seems worthy of a 
detailed study. 
Ето. 17.—A. Sargassum vulgare, C. Ag. 
B. Sargassum natans, L. (After Bürgesen.) 
Application of the same Principles to the Morphology of the 
Sargasso weed. 
Of all the unattached Brown Algs the most famous is the gulf-weed, 
found floating in large masses in the Sargasso Sea. Many authors, 
following Kuntze (1881, p. 197), have been content to regard this vege- 
tation as derived entirely from detached specimens, torn away from the 
reefs оп the West Indian coasts. This idea has been strongly combated 
by Sauvageau (1907), and recently Borgesen (1914, pp. 1-20) in a paper 
