FUNGI: THE IV I L LOW MILDEW. 



137 



filaments, the appendages. Each one of thes.e appendages is 

 coiled at the end into the form of a little hook. Because of 

 these hooked appendages this genus is called uncinula. This 

 rounded body is the perithecium. 



229, Asci and ascospores, \Yhile we are looking at a few of 

 these through the microscope with the low power, we should 

 press on the cover glass with a needle until we see a few of the 



Fig. 115. 



Willow mildew ; bit 

 of mycelium with 



Fig. 116. 



Fruit of willow mildew, showing hooked ap- 

 pendages. Genus uncinula. 



Fig. 117. 



Fruit body of an- 

 other mildew with 



erect < conidiophores Figures 1,6, Ti 7 .-Perithecia (perithecium) dichotomous appen- 



bearing chain of O f two powdery mildews, showing escape of dages O e n u s 



gonidia; gonidium at { containing the spores from the crushed microsphaera. 



left germinating. fruit bodies. 



perithecia rupture. If this is done carefully we see several 

 small^ovate sacs issue, each containing a number of spores, as 

 shown in fig. 116. Such a sac is an ascus, and the spores are 

 ascospores. 



