126 



MORPHOLOG 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 (Plasinopora viti- 

 cola), sliowingtuft or gonidiophores bearing 

 gonidia, also intercellular mycelium. 

 Millardet.) 



(After 



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 bclore fertilization, or the eggs, if 



