No. 387.| PLANT MORPHOLOGY AND PHYSIOLOGY. 217 
stem-rot. Both diseases are common in New York in the field and 
in the greenhouse. 
The Fusarium attacks chiefly the stem and larger branches, dis- 
coloring the wood and killing the cortex. The stems rarely become 
soft rotten. The plants die gradually, with yellowing and drying of 
the foliage. The fungus fruits rarely on the outside of stems, but 
more frequently in the cambium and medulla of stems long dead. 
The Rhizoctonia causes plants to wilt suddenly by rotting the stem 
at, or just below, the surface of the soil. The cortex readily separates 
from the wood. The medulla is attacked quite early, becoming water- 
soaked in appearance (or corky, when dry) and filled with hyphæ. 
