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AQUATIC PHYCOMYCETES 



Fig. 60. Ectrogellaceae and Thraustochytriaceae 



A. Ectrogella bacillariacearum Zopf, portion of the diatom Synedra, within 

 which part of a discharged sporangium is shown; outside the host, near orifice 

 of discharge tubes of fungus, are groups of encysted primary zoospores; above 

 arrow are secondary zoospores which have emerged from cysts, and above to 

 the right are primary zoospores with rudimentary flagella. B-C. Ectrogella 

 licmophorae Scherffel in Licmophora: B, two resting spores, upper one 

 apparently formed after a sexual process; supposed antheridial cell is empty 

 save for single globule; C, discharged zoosporangium with groups of encysted 

 primary zoospores at orifices of discharge tubes; base of each of latter 

 structures is thick-walled, forming a "forcing apparatus"; frustule of diatom 



