Parasitism in the Erysiphaceae. 309 



spores froni Triticum vulgare. 



Remarks. 



17 a, 17 b. Aug. 18. The 10 inocalated leaves all with radiating flecks o£ 

 mycelium bearing young conidiophores. Aug. 20. The infected leaves 

 with powdery masses of spores; - controls all free. 



20b. Aug. 23. A few flecks of mycelium on some of the inoculated 

 leaves. Aug 25. All the inoculated leaves with patches of mycelium 

 bearing conidiophores. Sept. 1. All the inoculated leaves with pow- 

 dery masses of spores. 



29 a. Aug. 27. All the inoculated leaves with patches of mycelium. 

 Sept. 2. All the infected leaves with powdery masses of spores. 



53 a. Sept. 7 Signs of infection on the 2 inoculated leaves. Sept. 9. 

 The 2 leaves with patches of mycelium and conidiophores. Sept. 12. 

 The 2 leaves with powdery masses of spores. 



Ö3d. Sept. 7. All the inoculated leaves with minute flecks of mycelium. 

 Sept. 9. The infected leaves with numerous large patches of mycelium 

 with numerous conidiophores, and abundaut spores. Sept. 12. infect- 

 ed leaves with powdery masses of spores. 



€2a. Sept. 14. A few flecks of mycelium on 2 of the inoculated leaves. 

 Sept. 16. Well-grown mycelial patch.es on the 3 inoculated leaves. 

 Sept. 17. AU the infected leaves with powdery masses of spores. 



spores from Ävena sativa. 



Remarks. 



12 a. Aug. 15. Flecks of mycelium on several of the inoculated leaves. 

 Aug. 16. Patches of mvcelium with conidiophores on the 6 inoculated 

 leaves. Aug 17. The"' 6 infected leaves bearing powdery masses of 

 spores; controls free. 



21b. Aug. 25. Flecks of mycelium on 1 of the inoculated leaves. Aug. 27. 

 2 of the inoculated leaves with flecks of mycelium. Sept. 3. The 3 

 inoculated leaves all with powdery masses of spores. 



30 a. Aug. 27. The 2 inoculated leaves with flecks of mycelium. Sept. 2. 

 Both leaves with powdery masses of spores; controls free. 



4-2 a. t^ept. 4. Signs of infection on 1 leaf. Sept. 7. 'Ihe 2 inoculated 

 leaves with patches of mycelium and conidiophores. 



46 a. Sept. 5. Slight signs of infection. Sept. 9. The 2 inoculated leaves 

 with powdery masses of spores; controls free. 



54a, 54b, 54c. Sept. 8. The 8 inoculated leaves all bearing radiating 

 flecks of mycelium with young conidiophores. Sept. 12. All the in- 

 fected leaves richly covered with powdery masses of spores. 



Beihefte Bot. Centralbl. Bd. XIV. 1903. 21 



