117 
Finally their walls thicken and become dark brown or brownish- 
grey. Ultimately the cells of the conidiophore itself not intre- 
quently become thick-walled and brown, and when separated are 
6 
4a, Thick-walled brown conidium twenty-four hours after germination 
ece.) 
Thick-walled brown Conidia.—In water and nutrient media 
these spores do not germinate under a period of at least twenty- 
ve days. ‘This resting period may be curtailed or even 
eliminated by- subjecting the spores to a temperature below 
‘reezing point or to the action of artificial gastric or pancreatic 
juice, The spores are equally susceptible with the pycnospores 
