DISEASES IN GREENHOUSE 103 



Shaw ^ and Rolfs,* who could not obtain 

 the perfect stage on culture media but 

 found it several times on the host. How- 

 ever, as the sweet pea Rhizoctonia pro- 

 duces macro-sclerotia (fig. 8), and as al- 

 ready pointed out by Shaw, the macro- 

 sclerotia produce the Corticium stage, the 

 sweet pea organism is therefore referred to 

 as Corticium vagum B. and C. 



Pathological Conditions of the 

 Host. Practical men, no doubt, like to 

 know what happens to the host plant when 

 it is attacked by the fungus. Rhizoctonia 

 when attacking hosts other than the sweet 

 pea, is found to parasitize the cambium 

 layer or growing part of the plant. With 

 the sweet pea, conditions are somewhat 



^ Shaw, F. J. F., The morphology and parasitism 6i 

 Rhizoctonia. Mem. Dept. Agr. India, Bot. ser. IV: 

 115-153, 1912. 



^ Rolfs, F. M., Potato failures, a second report. 

 Colo. Agr. Expt. Station Bui. 91, 1904. 



