Parasitism in the Erysiphaceae. 313 



spores from Trifolium pratense. 



R e m a r k s. 



10 a. Aug. 15. Fine mycelial threads on 1 leaf. Aug. 16. Patches of 



fiue mycelial threads with youug conidiophores on 2 leaves. Aug, 20. 



The 2 infected leaves with powdery masses of spores. 

 10 d. Aug. 20. 2 of the inoculated leaves with radiating patches of mycel- 



ium bearing groups of conidiophores 

 13 a, 18 b. Aug. 20. '6 of the inoculated leaves with fine radiating mycelial 



hyphae bearing small groups of conidiophores. Aug, 27. Infected 



leaves bearing here and there powdery masses of spores. 

 37 a, 37 e. Sept. 3. All the inoculated leaves with fine radiating mycelial 



hyphae. Sept. 5. The infected leaves bearing scattered groups of 



conidiophores on the mycelial patches. 

 58 a, 58 b. Sept, 10. Fine radiating mycelial hyphae on 1 of the inoculated 



leaves. Sept. 13. 3 of the inoculated leaves with radiating hyphae. 



Sept. 15. 4 of the inoculated leaves with mycelial patches. r^ept. 16. 



The mycelial patches vnth conidiophores. 



58 g. Sept. 15. Fine radiating mycelial hyphae on 2 of the inoculated 

 leave-s. 



spores from Pisum sativum. 



Rem a r ks. 



43 a. Sept. 3. Very fine radiatiog mycelial hyphae on all the infected 

 leaves. Sept. 4 Mycelial patches vigorous on the 3 infected leaves, 

 and bearing Clusters of conidiophores. Sept 9. The infected leaves 

 with powdery masses of spores; — controls all free. 



