18 
Research Bulletin A'O. p 
subject of thorough study by Appel and his coworkers (2, 4). Even- 
tually the plants infected with F. trichothecioides showed much se- 
verer symptoms than those inoculated with F. oxysponim (fig. 6). 
Eight plants died in the former sets, and 3 in the latter. Plants in- 
fected with F. tricJwtJiecioides showed such severe and rapid burning 
Fig. 4. — Leal rull and rii.-.cUtr iii iicld plant lii.- i'earl variety; .Kiigust 
H)V2, at the U. S. Substation at Mitchell, Neb. 
and drying up of leaves that the typical wilting phenomena were 
scarcely realized. The vascular bundles were blackened and the 
blackening extended even into the petiole and the leaf veins. This 
rapid killing was at first strictly localized on that side of the plant 
to which the inoculum had been applied, even in the leaf, where the 
leaflets on one side of the midrib would be afifected, and those on 
the other side not. Eventually in those cases in which killing of 
