PLATE 3 
Castor bean inflorescences infected with Sclerotinia ricini. 
A. —A nearly mature spike, showing typical appearance of the mold under natural 
conditions. Note drops exuding from new infections on the axis. X 3/4. 
B. —A similar spike with heavy production of mold. X 3/4- 
C. —A young spike infected by inoculation with ascospores. The mold was devel¬ 
oped, after infection occurred, by holding the specimen for 38 hours under a bell jar. 
Orlando, Fla., May, 1919. Natural size. 
