Parasitism in the Erysiphareae. 295 



spores from B. interruptus. 



R em ark s. 



1 c, Id. Aug. G. The 11 inoculated leaves with numerous patches of myce- 

 lium bearing youüg conidiophores. Aug. 8. The infected leaves cover- 

 ed with powdery luasses of spores; all control plants free. Aug. 21. 

 Oidiuni spread to controls. 



8 f. Aug. 11. The 4 inoculated leaves clearly infected. Aug. 15. The in- 

 fected leaves with powdery masses of spores. 



16 a, 1Gb. Aug. 18. All the inoculated leaves clearly infected. Aug. 19. 

 The infected leaves with powdery masses of spores. 



19 a, 19 b. Aug. 20. Nearly all the inoculated leaves showing signs of in- 

 fection. Aug. 23. All the infected leaves with very vigorous patches 

 of mycelium bearing powdery masses of spores; all controls free. 

 Aug. 31. Fungus spread to most of controls. 



28 a. Aug. 2G. Traces of infection visible. Aug. 27. 1 infected leaf with 

 conidiophores. Aug. 31. All the infected leaves with powdery masses 

 of spores. 



35a. Aug. 31. Faint signs of infection. Sept. 1. Infection more evident. 

 Sept. 4. All 3 inoculated leaves with powdery masses of spores. 



44:3,. Sept. 5. The 3 inoculated leaves with vigorous Oidium - patches 

 beai'ing powdery masses of spores; controls free. 



59a. Sept. 10. Faint signs of infection. 8ept. 12. All 3 leaves with vigor- 

 ous mycelial patches and a few conidiophores. Sept. 15. The infected 

 leaves with powdery masses of spores. 



04 a. Sept. 15. The 2 inoculated leaves with mycelial patches and young 

 conidiophores. Sept. 17. The leaves bearing powdeiy masses of spores. 



20* 



