1900] BOTRYTIS AND SCLEROTINIA 385 
of the forms could be changed into any other, or to prove defi- 
nitely that they are all distinct. To accomplish the former 
required that Botrytis be developed in a pure culture of one or 
both of the no-botrytis forms, that one or both of the typical 
no-botrytis forms be developed from Botrytis conidia, or that the 
typical Sclerotinia Libertiana be developed from the ordinary 
no-botrytis form or wice versa. 
Growth on various media.—Cultures of the three forms were 
made on a considerable variety of substances to test their effect 
on the organisms. These substances included various fruit 
decoctions, bread soaked with various nutrient juices and decoc- 
tions, and boiled fruits and vegetables of many different kinds. 
A detailed account of these cultures is unnecessary as in every 
case the growth was typical of the original material and no 
marked changes appeared. 
Effect of low temperature.— Here again no results were obtained. 
It was found that each of the forms, with proper nourishment, 
continued to grow almost down to the freezing point, but naturally 
with much less vigor at the lower temperatures. No other effect 
than this was observable with the no-botrytis forms. With 
Botrytis no conidia developed in cultures kept below 5° C., a 
feeble mycelium being the only growth. When put in a warm 
place, however, these cultures at once grew in the ordinary man- 
her, producing abundant conidia. 
Effect of darkness.—No marked effect was produced by growth 
in total darkness. ; 
Effect of starvation— Cultures made in pure gelatine with no 
nutrient addition showed nothing more marked than a feeble 
growth. 
Effect of solidity of substratum.—This was tested by using 
hutrient agar of different degrees of solidity. Growth was not 
aS Vigorous upon the hardest grades, but no other effect appeared. 
Effect of acid and alkaline media.—These experiments were 
Made by using as a nutrient medium prune juice of different 
degrees of acidity and alkalinity. The decoction was first care- 
fully neutralized by an experienced chemist, using sodium 
