168 Principles of Plant Culture. 
After the seed has been in the hot water ten minutes, 
remove the basket and plunge it into cold water, then spread 
it out to dry. The drying need not be thorough unless the 
seed is to be stored for a time. 
326. Fungi that Develop from Spores Surviving the 
Winter In or Upon the Soil, as the onion* and corn smuts,f 
cannot be prevented by disinfecting the seed. For these, we 
must depend upon surrounding the seed with some fungicide 
that will prevent infection of the young plant without affect- 
ing germination. For onion smut, a mixture of flowers of 
sulfur and air-slacked lime, sown with the seed, has proved 
decidedly beneficial, and is inexpensive. No preventive has 
yet been found for the corn smut. 
32%. Fungi the Spores of which Survive the Winter 
Within their Dead Host Plants, as in the club-root of the 
cabbaget and turnip, and the onion mildew,? may be held 
in check, to a degree, by burning the fungus-killed plants 
at the close of the season. 
328, Fungi that Infect their Host from Spores De= 
posited On the Aerial Parts of the plant, as the scab of 
the apple || and pear, and the downy grape-vine mildew { may 
be held in check by applying a fungicide (321) to the host 
plant itself, to destroy the spores as they alight upon it. 
Various compounds of copper and of sulfur are destructive 
to the spores of fungi, and, when properly applied, are 
harmless to the plant. The copper compounds are more 
generally satisfactory, since they have the greater adhesive 
power. 
* Eurocystis Cepule. } Ustilago Maydis. 
+ Plasmidiophora Brassice. ¢ Peronospora Schleideniana. 
|| Fusicladium dendriticum. | Peronospora viticola. 
