124 



AQUATIC PHYCOMYCETES 



- G " 



Fig. 12. Olpidiaceae 



/4. Nucleophaga amoebae Dangeard in Amoeba, mature sporangium in 

 nucleus of A. verrucosa. B-C. Sphacrita dangeardii Chatton and Brodsky 

 in Euglena: B, sporangium discharging its spores to outside of host; C, 

 thick-walled spiny resting spore. D. Sporangium of Olpidium endogenum 

 (Braun) Schroeter in cell of Zygnema, with last of zoospores just emerging. 

 E. Pleotrachelus fidgens Zopf in Pilobolus, discharging sporangium. F-G. 

 Rozella polyphagi Sparrow in prosporangium of Polyphagia euglenae: E, 

 mature sporangium, with several discharge papillae, completely filling para- 

 sitized prosporangium of host ; G, discharge of zoospores. H-I. Rozella sep- 

 tigena Cornu in hyphae of Achlya and Saprolegnia: H, resting spores in swol- 

 len lateral hyphal outgrowths of Saprolegnia spiralis ; at right is young zoo- 

 sporangium of parasite with a discharge papilla; around left-hand resting 

 spore the hyaline region, within which spines are formed, still persists; /, 

 portion of hypha of Achlya polyandra, showing sporangia of Rozella septigena 

 in various stages of development; in lowest segment wall of parasite has not 

 yet fused with that of host; at the tip the sporangium is discharging its zoo- 

 spores; in third cell from the top the strongly vacuolate stage of the proto- 

 plasm is shown. J. Olpidiomorpha pseudosporae Scherffel, zoospores, showing 



