80 



THE FUNGI WHICH CAUSE PLANT DISEASE 



The globular oospores fall into two classes; *^ first tuber- 

 culate or ridged; second, reticulated. These are illustrated in 

 Fig. 52. 



Fig. 52. — Oospores of Albugo 

 panduranae. 4. A. lepigoni. . 

 platensis. 9. A. occidentalis. 



. 1. A. Candida. 2. A. tropica. 

 5. A. swertia;. 6. A. tragopogonis. 

 10. A. portulacae. After Wilson 



3. A. ipomcesD- 

 7. A. bliti. 8. A. 



The conidia in germination usually produce several ovate 

 zoospores with two unequal, lateral cilia. After a brief period of 

 motility they became walled and produced germ tubes capable of 

 mfectmg susceptible hosts. The oospores after a period of rest 



