ZE 
spores as the more, if not the only, important ones in this respect. But 
oospores are as far as known never formed by the fungus; and if they 
are sometim?s formed they are at any rate of very little importance as 
spreaders of the disease. Furthermore the mycelium which is sometimes 
to be found in the seeds of diseased plants never gave rise to diseased 
plants in our experiments. 
The following conclusions seem allowed: 
a. there is no danger in planting in „infected” soil. 
b. seed material from a diseased crop does not carry the disease to 
the following crop. 
6. The incubation time usually lasts from 10 till 20 days, one month 
however being no exception. 
7. The liability of Zea Mais to infection is rather great at the seedling 
stage and augments till three or four leaves are formed. 
After this stage has been reached it begins to diminish; a plant three 
weeks or more old seems no longer liable. Experiments concerning the influence 
of cultural. conditions (way of planting, manuring, tillage of soil etc.) on 
the liability of plants do not yet permit any conclusions. 
8. The establishment of the fact that the disease is propagated only 
by means of the conidial fructification, gives a new aspect to the question 
of combating the disease. No effect can any longer be expected from soil- 
desinfection. And since no success was obtained by spraying with fungicides 
the most promising way seems to be the forbidding over large areas corn 
culture during a certain part of the year. 
Experiments on this line are in progress. 
