112 -TRANSACTIONS OF THE 
in contact with the embryonic leaves which they attack and 
again the characteristic diseased spots with its spore masses 
are produced. While this is not a case of blossom infec- 
tion, I mention it in connection with this paper to show 
how our conception of the attack and distribution of smut 
is becoming enlarged from the old idea of seedling in- 
fection only. 
INFECTION OF THE MAIZE PLANT.—Seedlings of maize 
are never infected. The embryonic tissue of the leaves 
and flowers, however, are. This happens as follows. The 
smut spores live saprophytically in the soil. After germ- 
ination and the formation of sporidia has taken place, these 
sporidia bud and produce secondary conidia. These, in 
turn, bud and this continues until some conidia reach the 
air and are transported by the wind to embryonic tissue, 
where infection takes place. Any embryonic tissue may be 
infected, and consequently we often find here flower in- 
fection occurring also. The smut spores, it should be stat- 
ed, in passing, are not capable of growing in pure water at 
all or only to a very limited extent. They only germinate 
in nutrient solution. The soil contains such a solution and 
especially favorable is the solution when the soil is rich 
in humus or when it contains much manure. This simple 
fact of spore germination only in nutrient solution being 
established, it is easily seen how well manured land planted 
to corn has been claimed by the farmer to yield more smut- 
ted plants than the soil not so rich in humus. Another 
lesson to the investigator, that after all many of the ex- 
periences of the farmer are founded upon fact and the in- 
vestigator may here often find the keynote for the solution 
of the problem. 
A number of plants could be taken up somewhat briefly 
as those already indicated, and show how they become at- 
tacked by smut. It must suffice, however, at present, to 
say that blossom infection has been shown to take place in 
Indian millet, in the Panicum species, and in Italian millet. 
Brefeld at present, as already mentioned previously, is 
experimenting on the covered smut of wheat and barley to 
see if the phenomenon of blossom infection does take place 
to some extent with these smuts. 
