422 



AQUATIC PHYCOMYCETES 



Fig. 26. Rhizidiaceae 



A-B. Solutoparies pythii Whiffen on Pythium sp. : A, mature zoosporangium; 

 B, zoospores emerging from gelatinous matrix left after dissolution of spo- 

 rangium wall. C-D. Siphonaria petersenii Karling: C, discharging sporangium; 

 D, sexually formed resting spore with three adherent male thalli. E-F. Sipho- 

 naria sparrowii Karling: E, emerged zoospores escaping from vesicle; F, 

 two germinating resting spores with thin-walled sporangia on their surface, 

 a male thallus on left. 



(A-B, Whiffen, 1942a; C-F, Karling, 1945d) 



