DISEASES DUE TO FUNGI 83 
and desiccation of the lowest leaves, followed by similar 
effects upon successive leaves from the base of the plant 
to the top. Finally the whole plant hangs limp and dies. 
On cutting open the stem the wood is seen to be a 
yellowish-brown, which discoloration extends up the 
plant practically to the growing point, and Verticillium 
albo-atrum is readily isolated. 
The disease is one of early spring and autumn, when 
the temperature is low, and is most destructive in cold 
houses and beds. Recommendations for the control of 
Verticillium wilt of the tomato are equally effective in 
the case of the cucumber and melon. 
VERTICILLIUM WILT OF THE SWEET-PEA 
During recent years growers who cultivate winter 
sweet-peas as a catch crop between the tomato seasons 
have been troubled by a wilt attributable to Verticilliwm 
albo-atrum. As in the case of other plants, the lowest 
leaves are first attacked—the fungus working rapidly up 
the plant, until the entire leaf surface is in a state of wilt, 
yellowing, and desiccation (Fig. 17). The wood is 
browned and the roots are in most cases entirely de- 
stroyed. The disease spreads rapidly, and the entire 
stock of plants may be destroyed within three weeks of 
the first appearance of the disease. In this case the 
disease progresses so rapidly in the plant, and the con- 
ditions of flowering are so restricted, that, except in 
special cases, the cultural methods of control advised for 
the tomato may have no value. 
When the disease is slight it may frequently be 
~ checked by an application of ‘‘ Cheshunt Compound,” 
but in bad cases the soil should be sterilized by steam 
before planting. 
Other Hosts of Verticilliwm albo-atrum.—Recent work 
has shown that V. albo-atrum attacks a wide range of 
plants, many of which are of interest to the commercial 
glasshouse grower. The writer has isolated this fungus 
