; 
apis 
ae 
A PARASITIC BOTRYTIS ON PEPPER AND LETTUCE. 61 
germinated and entered the tissues of the tomato. Here it 
either remained in the tissues, where it produced a rot, or the 
mycelium appeared on the surface and developed numerous 
conidiophores. The rotting of the fruit in the latter case 
was much slower. Carrots, potatoes and turnips, inoculated 
with conidia, rot slowly. The surface of these vegetables, if 
broken during the progress of the disease, became covered with 
a dark mass of conidia in less than twelve hours. 
The fungus, then, was able to produce direct infection in 
the majority of cases if water was present on the plant. It 
was able to propagate itself, and cause the “drop,” by its 
conidia, as well as by the mycelium. Infection by the my- 
celium always occurred on the leaves nearest to or on the 
ground. Infection experiments in the field were a failure in 
the majority of cases: 
Parasitism and Saprophytism: Because the fungus ex- 
hibited so many degrees of parasitism in the infection ex- 
periments, it seemed desirable to make a rather detailed study 
of this subject. This same question has troubled a number of 
authors and conflicting results have been obtained. 
De Bary (14), working with Sclerotinia Libertiana, found 
that the ascospores were not capable of producing direct in- 
fection, but must be saprophytically nourished before they 
possess the power of penetrating the living plant tissues. He 
believed that some substance, or substances, was secreted by 
the hypltai heed, ‘which: ‘dissql ved i}se: tissues .6f the host. Two phe- 
nomiend “eatild’ be distinfenishetl ‘it - ‘the Dredking down of the 
tissues; the death; ‘of ther cet] contents and the destruction of 
the cell walls "stcomplisitedl’ by ia -ellulose enzyme which dis- 
solves, swells and breskp. down the middle lamella of the cell 
walls. re 
Later, Kissling (81), investigating the development of 
Botrytis cinerea, like De Bary, found that the conidia were 
unable to bring about direct infection of the leaves of Gentiana 
lutea, although the young mycelium attacked the flowers. 
This peculiarity has been pointed out before, as one of the 
characteristics of the Sclerotinia, causing mummified fruits, 
