90 



Mycologia 



first separated are roughly pyramidal in shape, their bases resting 

 on the wall of the oogonium . Gradually the eggs become spher- 

 ical and acquire a thick, hyaline membrane. When they first be- 

 come spherical they show many oil globules situated on one side 

 of the egg (fig. io). These globules are at first only about 2^11 

 in diameter, but they gradually fuse until there are only two or 

 three larger ones from S/jl to 15/x in diameter. Finally these 

 globules fuse into a single one, which is about iG/jl in diameter, 

 and situated at the periphery of the egg. The eggs are then ripe. 



In old cultures an oogonium would often sprout a new one, the 

 old being emptied into the new (fig. 9). This process might be 

 repeated several times and the eggs be formed finally in the ter- 

 minal oogonium (fig. 8). 



Occasionally two oogonia were produced upon one branch, or 

 an antheridial filament was found coming from an oogonial 

 branch. 



University of North Carolina, Chapel Hill, N. C. 



Explanation of Plate LXIII 



Fig. I. The tip of a main hypha showing the gnarled condition of the sec- 

 ondary hyphae. X 155. 



Fig. 2. Main hypha showing sporangia and method of growth. X 155. 



Fig. 3. Spores encysted within the thin-walled sporangium. X 700. 



Fig. 4. Spores falling apart, the basal ring remaining. X 700. 



Fig. 5. Usually large basal cup with a few spores still remaining in it. 

 X 700. 



Fig. 6. Oogonium containing fully ripe eggs. Empty antheridia attached 



to the wall of the oogonium. X 700. 

 Fig. 7. Young oogonium with antheridium full of protoplasm. X 700. 

 Fig. 8. Showing double branching below the sporangia; antheridial 



branches ; and new oogonia formed from old ones. X 700. 

 Fig. 9. New oogonium forming from old one. X 700. 

 Fig. 10. Oogonium with young eggs and young antheridium. X 700. 



