396 BOTANICAL GAZETTE [JUNE 
simply a slight discoloration and moist appearance of the flesh, 
no outward change appearing. No fungus was visible at first to 
the naked eye. When cut in two and kept moist over night a 
vigorous growth of Sotrytis cinerea appeared on the affected 
parts, most abundant where worst affected and shading off toward 
the most recently affected portion, where no conidia developed. 
The interior was found to be filled with a vigorous mycelium 
similar to that in the lettuce and other diseases (fig. 49). 
Cultures on various media gave the usual Botrytis development, 
conidia being developed abundantly when badly affected tissue 
was used for infection, but very sparsely on newly affected 
portions or in cultures made therefrom. In the latter cultures 
sclerotia were quite numerous, being long, narrow, and thin, 
closely joined to the substratum in the characteristic Botrytis 
manner. It was found possible to infect sound roots with 
conidia by cutting out a plug, inserting the spores, and replac- 
ing the part cut out, There was no question that the rotting in 
this case was caused by Botrytis cinerea, pure and simple. The 
case described by Potter (8) is entirely similar. De Bary (4) 
and Coemans (1) found rotting of turnips, carrots, etc., caused 
by Sclerotinia Libertiana ( Peziza Sclerotiorum). The writer has 
found by infecting turnips with Botrytis and Sclerotinia that an 
entirely similar effect is obtained and an intercellular mycelium 
produced which is quite indistinguishable. By making cultures, 
however, from the affected tissue, sclerotia are obtained, and in 
the one case conidia, which distinguish the two forms at once. 
This case, therefore, shows once more how easily confused these 
two forms are, having so similar a mycelium and effect, while at 
the same time it furnishes strong proof, when thoroughly looked 
into, of their entire distinctness. 
Rotting of various fruits caused by Botrytis has been 
described by Brefeld (2) and Wehmer (9). 
A rotting of onions is often caused by Botrytis and has 
been described by Halsted (6), Sorauer Lat, 294), and Frank 
(42,5: 503). The writer found a similar case in Munich, where 
the affected tissue was permeated with a mycelium (/g. 48). 
Ee eae oe 
