'33 



BOTANY. 



Synopsis. 



Vegetative part of the plant : mycelium on the surface of 

 the host sends suckers (haustoria) into the cells of the 

 host. ' 



Propagative stage of the plant: short erect threads which 

 Willow mildew, j bear chains of spores (gonidia). 



Fruiting part of the plant (perfect stage). 

 Perithecium with hooked appendages. 

 Perithecium contains sacs (asci). 



The sacs contain the spores (ascospores). 

 Material. Dried and pressed leaves of willow with the white mildew, also 

 older stages showing the numerous black "specks," the fruit bodies, of the 

 mildew. Other species of the mildew may be used if preferred. 

 Microscope, etc. 



