286 THE MARINE BOTANIST. 



titions. ^' Thus if a whole frond of Bryopsis 

 plumosa be placed on a piece of glass, under water, 

 and the tip of one of its branches be wounded, the 

 contents of the frond may be pressed out through 

 the lacerated part, leaving nothing but an empty 

 skin, and showing that there is no internal dia- 

 phragm in any part of the tube." In Codium the 

 filaments are woven together into fronds of spongy 

 substance and various forms. 



Bryopsis, though of simpler structure, appears 

 more perfect, from the regularity and beauty of its 

 pinnate fronds, resembling tufts of miniature green 

 feathers. The filaments in Vaucheria are densely 

 tufted, and often intertwined together, forming 

 cushion-like tufts. Many of the species are found 

 in ponds, ditches, and on damp earth ; the marine 

 kinds alone are described in this work. 



