126 



MOfiPHOLOG Y. 



power the two cilia on the end may be seen, or we may make 

 them more distinct by treatment with Schultz's solution, draw- 

 ing some under the cover glass. The zoogonidium is oval and 

 the cilia are at the pointed end. After they have been at rest 



Fig. 139- 

 Downy mildew of grape (Plasmopora viti- 

 cola), showing tuft of gonidiophores bearing 

 gonidia, also intercellular mycelium. (After 

 Millardet.) 



Fig. 140. 

 Phytophthora infestans showing pe- 

 culiar branches ; gonidia below. 



for some time they often slip out of the thin wall, and swim 

 again, this time with the two cilia on the side, and then the 

 zoogonidium is this time more or less bean-shaped or reniform. 



283 Sexual reproduction of saprolegnia When such cultures are older 



we often see large rounded bodies either at the end of a thread, or of a 

 branch, which contain several smaller rounded bodies as shown in fig. 135. 

 These are the oogonia (unless the plant is attacked by a parasite), and the 

 round bodies inside are the egg cells, if beiore fertilization, or the eggs, if 



