PLATE 13 



Physoderma zeae-maydis: Various stages in the germination of sporangia, formation 

 of zoospore, and germination of zoospore. 



a. — Sporangium. 



b, c, d. — Opening sporangia showing the early stages of zoospore formation. 



e. — Mature zoospores escaping through the ruptured apex of the endosporangium. 



/• — The collapsing endosporongium after the zoospores have escaped. A single zoo- 

 spore remained within the sporangium. The active stage of zoospores remaining 

 within the sporangium was easily studied. 



g. — Zoospores. 



h. — Germinating zoospores. 



