DESCRIPTION OF PLATES VI and VII. 



(Sclerospora yraminicola (Sacc.) Schroet). 



PLATE VI. 



Downy mildew of Andropogon Sorghum. 



Fig. 1. Second form, about the beginning of oospore-formation. 



., 2. First form, early stage, upper surface of leaf. 



., 3. Ditto later stage, lower surface of leaf. 



., 4. Third form, late stage. 



,, 5. Ditto very early stage. 



PLATE VI r. 



Fig. 1. Conidiophore of Sc, graminicola from Pennisetum, showing the short 

 papilla?. 

 „ 2. Early stage of development of the sporangia from Pennisetum. 

 „ 3. Later stage of ditto ditto. 



„ 4. Sporangia from Pennisetum. Note the apical thickening which 



swells to form the papilla of discharge. 

 ., 5. Early stage of development of the conidia of Sc. graminicola var. 

 Andropogonis Sonjhi from Sorghum. 

 Figs. 6 & 7. Later stage of ditto. Note the long papilla? on which the 



spores are borne. 

 Fig. 8. Conidia from Sorghum. 

 „ 9. Ditto «erminatin<r. 



