SAPROLEGNIA 1 29 



F. Asexual Reproduction: 



1. Carefully study again the terminal sporangia. 

 How many times longer than broad are they? 

 Compare the thickness of the sporangium walls 

 with those of the remainder of the hyphae. Can 

 you detect any variations in the thickness of the 

 sporangium walls? If so, describe and explain. 

 Describe and account for the shape of the free tip 

 of the sporangium. 



2. Describe the shape of the zoospores, or swarm- 

 spores; their size; number in one sporangium; 

 color. Are they all alike in these characters? 



3. Endeavor to find swarm-spores escaping from a 

 sporangium. Do they merely float away, or have 

 they power of locomotion? Look for organs of 

 locomotion? If you find them, describe their 

 number, length, action, and general appearance. 

 Do they precede or follow the zoospore as it moves 

 through the water? 



4. Do the zoospores ever move up or down through 

 the water so as to be out of focus? If so, consider 

 thoughtfully the thickness of the film of water 

 in which they are, and try to form some conception 

 of the size of a body that can move vertically 

 beyond the range of vision in a film so thin. Briefly 

 discuss this point. 



5. Do you see any evidence that any two of these 

 swarm-spores are in the process of fusion? Do 

 their movements appear to be directed, or not? 



6. Make suitable drawings to illustrate all points 

 observed under F. 



G. Sexual Reproduction: 



i. Under suitable conditions female reproductive 

 organs, oogonia, develop on certain hyphae near the 



