PLATE B 



Sheath and culm of com plant showing the effects of Physoderma zeae-mazydis. In 

 these parts there is a large production of sporangia, which causes the dark spots, as is 

 true in case of the midrib of the blade as seen in Plate A. In some cases the entire 

 sheath is darkened and the nodes completely girdled by the fungus. 



