120 
tried out. The discovery of the important points in the life his- 
tory of these parasites has made possible great progress in the 
development of methods of seed treatment since, in many cases at 
least, the spores are carried on the seed. Many chemical sub- 
stances have been tested and various methods employed in their 
lic. 6. Head smut of sorghum on Red Amber Sorgo. 
use. The hot-water method of seed treatment also has proved of 
value in some cases. 
There are, however, certain disadvantages in any method of 
seed treatment. [or one thing, it is difficult to get farmers to 
apply treatments which involve any extra trouble and expense. 
Further, all of the effective seed treatments, unless very carefully 
handled, are likely to cause considerable injury to the seed. It is 
