PLATE 21 



A. — A near view of the thick down of conidiophores which has been produced on 

 the upper surface of a badly diseased maize leaf. This gives an idea of the vast num- 

 bers of conidiophores which are borne on even a small area. The regions where they 

 are formed most abundantly correspond in general to the stripings of the leaf. The 

 layer of dew in which the conidiophores were produced has just dried. X 2. 



B. — Upper surface of a badly infected maize leaf from a maturing plant. Conidi- 

 ophore production is in this case restricted to the yellowish white stripes like those 

 shown in the colored plate. X iX- 



C. — Upper surface of the middle portion of a maize leaf from a very young plant 

 which has only recently developed the markings of the disease. The stripes are 

 seen to be covered with conidiophores even up to the ends. X iK- 



