Parasitism in the Erysiphaceae. 303 



spores from B. commutatus. 



R e ni a r k s. 



15 a, 15b, 15e. Aug. 18. Flecks of mycelium bearing conidiopbores on 10 

 of tbe inoculated leaves. Aug 20. The 11 inoculated leaves all witli 

 powdery masses of spores ; — coütrols all free. 



24 a. Aug. 24. Flecks of mycelium ou tlie 3 inoculated leaves. Aug. 31. 

 The infected leaves richly covered vfith powdery masses of spores. 



36a. Aug. 30. All the inoculated leaves with patches of mycelium and 

 a fevp conidiophores. Aug. 31. The 3 leaves with powdery masses of 

 spores; — controls all free. 



41 a. Sept. 4. 2 of the inoculated leaves with patches of mycelium. 

 Sept. 7. All the infected leaves with powdery masses of spores. 



66a. Sept. 15. The inoculated leaf with patches of mycelium and young 

 conidiophores. Sept. 17. The infected leaf with powdery masses of 

 spores. 



15 g, 15h. Aug. 19. 4 of the inoculated leaves vpith minute flecks of mycel- 

 ium. Aug. 20. The infected leaves bearing spores Aug. 21 5 of 

 the inoculated leaves bearing more or less powdery masses of spores. 



24 b, 24 c. Aug. 24 Faint signs of infection. Aug. 25. Flecks of mycel- 

 ium on 4 of the inoculated leaves. Aug. 31. The 6 infected leaves 

 covered with powdery masses of spores. 



36b, 36c. ,Subinfection' only. Sept. 7. A f ew scattered conidiophores, at 

 the exact places only where spores were sown, on 5 of the inoculated 

 leaves. 



60 c, 60 d. .Subinfection' only. f^ept. 15. A few isolated conidiophores on 

 3 of the inoculated leaves just where the spores were sown. Sept. 16. 

 Scattered conidiophores and a few weak patches of myceUum on 2 of 

 the inoculated leaves, and a few scattered conidiophores on the other 2. 



