I 
362 REPORT OF THE COMMISSIONER OF AGRICULTURE. 
It occurs in Germany, France, Italy, England, and the United ~ 
States. In the latter country it seems to be very generally dis- 
tributed, as specimens have been sentto the Department from Maine, 
Massachusetts, Wisconsin, Pennsylvania, Louisiana, and the District 
of Columbia. An allied species, G. legwminis, is also found in Cali- 
fornia, upon a-different host, however. 
It is the pods and the beans they contain that are chiefly affected, 
the other parts of the plants being rarely if ever attacked. Frank 
attempted toinfect the leaves and stems, but with no result. Healso 
tried to infect different plants, but failed in this also. In this coun- 
try, however, the disease attacks water-melon rinds as well as beans. | 
(6) EXTERNAL CHARACTERS. 
The disease makes its appearance as a small, reddish-brown spot 
which grows rapidly, soon becoming black in the center. With the 
exception of a narrow line on its circumference this black center 
afterwards turns to a dirty gray or light brown. 
The spots are usually round, from 2"" to 6™™ in diameter, the 
largest rarely exceeding a centimeter. 
They are composed of a reddish-brown band on the outside, fol- 
lowed within (in most cases) by a narrow black band, and have a 
brownish or dirty white center, over which is a mass of light-colored 
powder. The spots may grow until they extend entirely across the 
pod, and several sometimes coalesce, forming large brown patches 
that nearly cover its surface (Fig. 1). From the first, these spots are 
sunken below the surface of the healthy tissue, and as the disease 
progresses they sink deeper and the pod becomes more and more 
shrunken, while the bean within may also become diseased and 
shriveled untilit has but asmall fraction of itsnormal size (Fig, 3, b). 
(¢@) CONDITIONS FAVORING THE DISEASE, 
The young fruit is most subject to attack, and if the parasite gains 
a footing in the partly-grown pods, it is, of course, very disastrous, 
as the growth of the bean is checked, even when the latter is not dis- 
eased. It will readily be seen that the parasite, if at all prevalent, 
is a very injurious one to the crop; and as a matter of fact this is 
often the case where the conditions are favorable to the fungus. 
These conditions are simply dampness of soil and atmosphere, which, 
although favorable to nearly all parasitic fungi, seem to be more 
necessary to the development of this particular disease than it does 
in the majority of cases, and an airy, dry situation for the plants is 
the best means of preventing an attack. 
(d) BOTANICAL CHARACTERS. 
As found upon the bean pod the mature fungus consists of a my- 
celium, which penetrates the tissue of the pod and bean, sending 
basidia to the surface, which in turn bear numerous spores. 
In general the mycelium is colored, but portions may be uncolored, 
even where the remainder is quite dark. Itis branching, septate, of 
variable diameter, and contains granular protoplasm and large oil 
drops (Fig. 4, 0). 
The basidia (Fig. 4, c) are colorless and straight, with bluntly- 
rounded tips, and are borne in clusters. 
