PLATE 8 
Apparently healthy com plant which reacted for aluminum and iron. 
A. —This plant was a normal growing stalk of Reid Yellow Dent. The leaves 
and the portion of the stalk above the ear were trimmed off in the field. The stalk 
was sectioned longitudinally in the laboratory and tested for aluminum and iron 
compounds. 
B. —Basal tissues of the stalk shown in A. The vascular bundles which are dark 
gave reaction for aluminum and iron. Note the lowest roots to the left. They were 
not functioning even though in moist soil. No rot lesions were found on these roots. 
This picture was made on the same scale as Plate 7, B. 
