[Vol. 2 



440 



ANNALS OF THE MISSOURI BOTANICAL GARDEN 



branched and lobed, sometimes botryoid, and they are ulti- 



mately divided into short, ovate cells, 



arranged in 



short 



chains, or elbowed, and producing branches in a more or less 

 dichotomous fashion (figs. 7 and 8). In culture the denser 



Fig. 6. Rhizoctonia Solani : 

 Vegetative hyphae. 



Fig. 7. Rhizoctonia Solani: a, 

 young hyphae from young sclero- 

 tial tuft on lettuce; b, older cells 

 from same source. 



masses give rise to sclerotia. With maturity these hyphae be- 

 come light brown in color, they break up readily into short 

 hyphal lengths or single cells, the individuals of which bear 

 some resemblance to conidia. However, they could not easily 

 be mistaken for spores, although they may function as such, 

 inasmuch as most of them may germinate within a few hours 

 when placed under suitable conditions. I have previously de- 

 scribed ('99) this process as follows: 



"So far as observed, germination is always by the protrusion 

 of a tube through a septum. When several cells are connected, 

 a germ tube from one cell may pass into and through its 



neighbor, * 



* * * 



and thus peculiar appearances may result. 



Some of the cells of the hyphal chains seem to be devoid of 

 protoplasm, and from neighboring protoplasmic cells the germ 



