PLATE XLV 



Rheosporangium aphanidermatus: 



Figs. I, 2, 3, 4, 5. — Sections of sporangia showing various stages of cleavage into 

 zoospores. Figure 3 shows mitochondria and, at the periphery, fragments of cilia. 

 X2,ooo. 



Fig. 6. — Segment of mycelium showing accumulation of cytoplasm characteristic 

 of old aquatic cultures; living material. X750. 



Fig. 7. — Oospore within the old oogonial wall, antheridial wall attached. From 

 typical tmstained, living material produced in aquatic culture. X 1,500. 



Fig. 8. — Young oogonium and antheridium not yet cut off from the parent hyphae. 

 Fixed and stained, but unsectioned. X2,ooo. See also Plate XLVIII, figures 2 

 and 3. 



