CCENOBIE^ 



297 



protoplasm again breaks up into zoospores, which swarm about for twenty 

 or forty minutes within a sac which protrudes out of the protoplasm. 

 When they come to rest, they arrange themselves within the sac into a 

 small net consisting of from 200 to 300 cells, which gradually grows to 



Fig. 260. — Hydrodictyon idricnlatujii Roth. A, net (natural size). _ B^ mesh ( x lo). C, mepazoo 

 sporange (x 300). D, megazoospores (x 600). E^ gametange with zoogameles ( X 300). (After 

 Cohn.) 



one of the ordinary size. In some of the polyhedra smaller and more 

 numerous microzoospores are formed ; but they also appear to unite 

 again into a net without displaying sexual functions. 



Literature. 



Nageli— Gattungen einzelliger Algen, 1849, P- 92- 



Braun— VerjUngung in der Natur, 1851 (Ray Soc, Bot. and Phys. Mem., 1853) ; and 



Algse unicellulares, 1855. 

 Pringsheim— Monber. Bed. Akad., i860, p. 775 (Quart. Journ. Micr, Sc, 1862, pp. 



54 and 104). 



