FUNGI: SAPROLEGNIA. 



183 



Fertilization in saprolegnia, tube of antheridium carrying in the nucleus of the sperm cell 

 > the egg. In the right-hand figure a smaller sperm nucleus is about to fust with the 

 ucleus of the egg. (After Humphrey and Trow.) 



r ig. 200. 

 Branching hypha of Peronospora alsinea 



Fig. *,.. 



Branched hypha of downy mildew 

 of grape showing peculiar branching 

 (Plasmopara viticola). 



