130 MORPHOLOGY AND LIFE HISTORY 



body of the fly, and each oogonium develops a 

 number of eggs. If oogonia are found, describe 

 them carefully as directed above (F, i) for sporangia, 

 making suitable drawings. Do they always occur 

 at the end of the hypha that bears them? 

 2. The male reproductive organs are antheridial fila- 

 ments, growing either below the oogonia or on 

 adjacent hyphae. 1 They are of smaller diameter 

 then the hyphae. If you find these organs, care- 

 fully describe their appearance, contents, size, and 

 relation to the oogonia. Illustrate all points ob- 

 served with suitable drawings. 

 H. General Questions: 



1. Do you find a physiological division of labor in 

 Saprolegnia? If so, describe in detail. 



2. State why you consider this plant higher or lower in 

 the scale of life than Phycomyces or Fucus. 



3. Describe all methods of dissemination of Saprolegnia 

 that you can think of. 



development of the egg-cell without fertilization (i.e., by par- 

 thenogenesis) is more usual than fertilization in Saprolegnia, so that fer- 

 tilization, or even antheridial filaments, may be wanting. 



