49 3 Brown . — Studies in the Physiology of Parasitism . IV. 
Summary. 
1. Two types of enzymic preparations derivable from cultures of 
Botrytis cinerea are described. These are : 
(a) Watery extracts of the ground mycelium. 
(b) The media in which germination and growth have taken place. 
2. The amounts of (a) enzyme, {b) enzyme-retarding substances present 
in these under various experimental conditions (density of sowing, age of 
culture, nature of medium) were determined in each case. 
3. A discussion is given of the bearing of these results on the technique 
of enzyme extraction on the one hand, and on the process of enzyme 
excretion by fungi on the other. 
