327 
Infection of the Host.—The conidia of Botrytis show ver 
great variability in their power of attacking plants, this jepeut 
ing upon the particular strain of the fungus, upon the host, and 
upon the anitatal conditions in the environment at the time of 
among gentians found e conidia could not attack the 
leaves. Infection occurred through the stigma and anthers, 
and this agrees wi ordhausen’s resultst in which non-cuticu- 
larised organs succumbed readily to the attacks of germinating 
conidia, whilst only under certain special conditions of humidity, 
lack of light or flaccidity could the leaves be infected. Pottert 
found no difficulty in directly infecting turnips and potato 
haulms with the conidia of Botrytis, whilst Brooks§ could only 
infect lettuce plants after they ha en kept for some days in 
darkness or were yellowing. Brooks and Baritlett|| were unable 
to infect gooseberry bushes with conidia even when these were 
placed in wounds in the cortex. Tubeuf§ and Behrens** found 
2 “‘ woody texture no definite action could be established in any 
case’’. As was pointed out by Marshall Ward (loc. cit.) conidia 
may in almost all cases be rendered capable of penetrating a 
cuticularised surface of a leaf or stem if their germ tubes be 
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* Kissling, E. Zur Biologie der Botrytis cinerea, Hedwigia vol. 28, 1889. 
+ Nordhausen, M. Beitrage zur Biologie parasitirer Pilze, Jahrb. Wiss. 
Bot. 1899. 
t Potter, M. C. Rottenness of Turnips and Swedes in Store, Journ. Bd. 
Agric., vol. iii, 1896. 
§ Brooks, F. T. Observations on the Biology of Botrytis cinerea, Ann. 
Bot., vol. xxii, 1908. 
| Brooks, F. T., and Bartlett, A. W. Two Diseases of Gooseberry Bushes, 
Ann. Mycol., vol. viii, 191 
“ Yubeuf, V. K. F. Beitrage zur Kenntnis der Baumkrankheiten, Berlin, 
1888. 
** Behrens, J. Phytopathologische Notizen, Zeit. f. Pflanzenkrank Bd. 
v, 1895. 
+t Massee, G. A Conifer Disease, Journ. Bd. Agric., vol. x, 1903. 
_ tt Brierley, W. B. Note ona Botrytis Disease of Fig Trees, Kew Bull. 
1916, p. 225. 
