976 



XIV. ALGM. 



of the filament by tlie formation of a diaphragm. Then the contained matter coagulates in small masses, 

 ■which become more and more sharply defined, and end by forming so many zoospores. These phenomena 

 succeed each other very rapidly; often in less than an hour the granular matter becomes condensed at 

 the top of a filament, the septum forms, and the zoospores appear. Finally the tube, -which has a small 



_^ „ Young 



sporangium to wMch are 



attached the (? filampnts. 



(Pringsheim.) 



S. ferax. 



Extremity of a 



filament ^mag. 380). 



(Thuret.) 



S.ferax. 



Filament, older, showing a 



cdl in the upper part of the 



tube, in*which the zooaporea 



are formed. 



Saprolegnia dioica. 



Filament, showing the phenomena of 



fertilization. (Pringsheim.) 



Saprolegnia. 



Sporangium, showing 



the places where the 



openings will be formed. 



(Pringsheim.) 



J?, monoica. 

 r, sterile brnnch ; r', branch swollen 

 into an antheridium ; s, sporangium 

 (oogonium) ; t, tubes of communica- 

 tion of the antheridia with the spores. 



Saprolegnia. 

 Sporangium (oogonium), 

 older, showing the thin 

 parts of the walls corre- 

 sponding to the tubes, and 

 the zoospores completely 

 developed. 

 (Pringsheim.) 



S. ferax. 

 Filament in which 

 the zoospores are 

 completely formed, 

 and on the point of 

 escaping from the 

 filament. (Thuret.) 



, S. ferax. 

 Filament emitting the 

 zoospores. (Thuret. ) 



