FUCUS VESICULOSUS. 



81 



of a cepta, that gradually grows more distinct until it crosses 

 the whole, when one-half of the fertilized oosphere puts out 

 little protuberances which develop into roots, and the other half 

 grows into an expanded frond that developes in its turn con- 

 ceptacles, oogonia and oospheres, or antheridia, and antherozoid.* 



[As a note to the excellent article of Mrs. Stowell's we give 

 plates of the two most common varieties of the sea-wracks that 

 are apt to be substituted for the genuine anti-fat one. The first, 

 or Fucus Serratus, can be readily detected if any attention is 

 paid to the contour of the leaves. 



You will notice the leaves are dentated, 

 or serrated, and from this fact it derives 

 its specific name, serratus. It has no air 

 vessels, or bladders, as seen in the gen- 

 uine obese-reducing Fucus, which gives 

 it its specific name Vesiculosus. 



The other common variety, and one 

 most apt to be confounded witn the F. 

 Vesiculosus, is the Fucus Nodosus, 'as seen 

 in the accompanying plate. 



This knotted, or clubbed-wrack resem- 

 bles considerably the genuine medical 

 variety, but can be distinguished from 

 it by the absence of any mid-rib, and 

 the vesicles along each side of the mid- 

 rib., Any enlargement the Nodosus has, 

 that simulates the Vesicutosus variety, is 

 a bulbous enlargement of the whole frond. 

 The common name, "wrack," which all these species of sea- 

 weed bear, is derived from the Channel Island vernacular, where 

 it is known as vraic, a patois of the French varec, which means 

 "sea : weed." Another vernacular name for the Fucus Vesiculo- 

 sus is (from its color) "Black Tang." EDITOR OF LEONARD'S 

 JOURNAL.] 



^Authorities Harvey, Neries Boreali-Americana. Sach's Botany, page 227. Thuret. Ann. 

 des Sci. Nat., Ser. IV., Tom. 2. 



<. 8. Fucus Nodosus. 



Natural size. 



