582 
Journal of Agricultural Research 
Vol. XI, No. ii 
RELATION OF THE FUNGUS TO THE RESISTANT PLANT 
After finding that the fungus was able to penetrate seedlings of the 
resistant strain of flax in tube cultures, experiments were planned to 
determine whether or not the fungus was entering the resistant plants 
growing in infected soil, and, if so, why it was not able to invade the plant 
and cause wilt. It was found by inoculation experiments that the fungus 
was unable to produce wilt in resistant plants when introduced through 
wounds, although infection was obtained by inoculating plants of the 
susceptible strain. Inoculations were made by inserting bits of mycelium 
Fig. 7.—Cross section of the vascular tissues of a susceptible flax plant, showing the invading hyphae of 
Fusarium Uni. Camera-lueida drawing. 
into needle wounds in the stems of plants. Some were inoculated just 
above and others just below the soil surface. Stems inoculated above 
ground were wrapped with moist cotton, while those inoculated below 
the surface of the ground were covered by replacing the soil. Table I 
gives the results of these inoculations. It will be seen from this table 
that the inoculations made in the field were less successful than those 
made in the greenhouse. The plants in the field were in the flowering 
stage, which is rather late for infection, and were growing under conditions 
where the moisture could not be satisfactorily controlled. In the green¬ 
house young plants were inoculated and kept under better controlled 
moisture conditions. 
