492 
Journal of Agricultural Research 
Vol. XI, No. 10 
that the host may be more susceptible at this age; and the other that 
picking of the fruit, especially if the foliage is wet with dew or from 
rain, results in a liberal distribution of the spores. 
That strong winds may be responsible for severe outbreaks of this 
and other diseases is evident from the fact that Cook ( 6 , p. 517-518) 
found a serious outbreak in a certain section of New Jersey previously 
visited by a severe windstorm. It is, of course, natural to conclude, 
as Cook assumed and the writer has frequently observed, that injury 
to pods and foliage during such a storm would add to the chances of 
infection. It is believed that the part played by the wind in dissemi¬ 
nating fungus spores has been very greatly underestimated. It is a 
well-known fact that the pollen of pine trees is carried long distances. 
Dr. Albert Mann, of the Bureau of Plant Industry, found 1 a large 
variety of fungus spores collected on a gelatin plate exposed for about 
15 minutes at a distance of 1 mile above the surface of the earth. This 
readily shows that spores are freely air-borne over long distances, and 
this fact alone may account for the serious outbreak of a disease in 
isolated sections. 
Owing to the fact that the causal organism can readily be isolated 
from the seed, it is likely that this affords the principal means of dis¬ 
tributing it over long distances. Fruiting bodies have also been found 
on infected seed. This shows the great necessity of saving seed only 
from fields where this disease does not occur. 
CULTURAL CHARACTERISTICS OF THE FUNGUS 
The fungus produces hyphae on nearly all of the culture media in 
ordinary use. The pycnidia, on the other hand, are rarely produced 
on agars, but freely on media containing starch, such as rice or corn 
meal. A study of the growth and production of fruiting bodies was 
made on the following media: String-bean agar, Irish potato agar, beef 
agar, corn-meal agar, cooked rice, cooked com meal, potato cylinders, 
and stems of Melilotus alba. These media were selected because they 
are in common use in the laboratory of Cotton, Truck, and Forage Crop 
disease investigations, and because some (com meal and rice) were 
known to be particularly favorable for the growth of other very similar 
organisms, thus affording an opportunity for comparison. Other media 
might have served the same purpose. 
The experiment was carried out by inoculating five tubes (100 c. c. 
flasks, in case of com meal) with spores from a io-day-old culture on 
stems of Melilotus alba. After inoculation the tubes were kept in the 
light and exposed to the temperature of the laboratory room (2i°-25°C.). 
String-bean agar. —This on the whole has been a poor medium for this fungus. 
Growth of hyphae started promptly and was visible in two days in slanted tubes of 
1 Unpublished data. 
