1a 
dormant smut mycelium. When such a kernel is planted in the 
ground it produces the young wheat plant. At the same time, 
however, the mycelium of the parasite grows and develops in the 
embryonic tissues of the host. When the latter begins to form its 
flowers the fungus develops very rapidly and in place of the normal 
seed and adjacent tissues the smut spores are formed. Inoculation 
then takes place at the flowering period of the host. In this smut 
there can be no danger from storing the seed in smutted sacks or 
threshing with contaminated machinery. The infection takes place 
only at the flowering period of the host. The fungus lies dormant 
in the seed and when the latter germinates to form a new plant the 
mycelium renews its development. 
flag or Leaf Smut of Wheat.—The life history of the parasite 
causing this disease is similar to the smut which causes bunt. The 
infection takes place in the seedling stage from spores present 
either on the seed or in the soil. The infected plants, however, 
are very greatly stunted and commonly are prevented from head- 
ing, or if an infected plant does head, very little seed is produced. 
The fungus finally develops principally in the leaves and to some 
extent in the stems. Long lines of black tissue appear between 
the veins of the leaves due to the formation of the spores in linear 
masses. ‘These later rupture and the spores escape. Leaf smut 
or flag smut is reported as particularly destructive in Australia and 
South Africa. Recently it was found in southern Illinois and ad- 
jacent regions, and is recognized as a disease of serious potential 
danger. The fact that infection takes place from spores present 
in the soil as well as from spores on the seed makes it a particu- 
larly persistent disease. 
The Loose and Covered Smut of Oats—The loose smut of oats 
is caused by Ustilago avenae. The infection of the oat plant takes 
place in the seedling stage from spores adhering to the grain. The 
fungous mycelium develops in the infected plant and when the lat- 
ter blooms the characteristic black heads appear. The flowers of 
the infected plants are almost completely replaced with the fine, 
black, dusty spores of the parasite. The glumes or chaff of the 
oat are involved as. well as the kernel and the destructiveness of 
this disease is at once apparent. Shortly after the diseased in- 
