159 
of which the plants (lied. The loss, however, was trifling, amounting 
to only 4 or 5 per cent. The seedlings which were infected in later 
stages gave only 1 or 2 per cent of loss. The last set, with open sheath, 
remained sound. 
The few plants which became diseased so early, and which died com¬ 
pletely, suggested in their appearance the smutted maize seedlings which 
Kuhn observed and described. The time of the appearance of the smut 
swellings after the infection also agreed with Killings statement. 
I now waited, expecting that, as had happened with oat and millet 
smut, the corn smut would appear upon the fully developed plant, 
especially in the fertile spikes, but I waited in vain. Already, the fact 
that, from this time on, the strongly developing axes remained entirely 
sound had made me suspicious, and when autumn came, and the ears 
were formed, not one out of many hundred plants was smutty . 
Before the issue of this experiment, which had consumed several 
months, I stood at first helpless. The infections were made as care¬ 
fully as possible, and the failure was not to be explained by these. This 
must have other causes. All reflections in the course of the winter led 
me back to this conclusion, that probably in maize the infection of young 
seedlings could not lead to the production of smut in the full-grown 
plant , as is the case in smut forms living in the grain. At the time of 
this first series of experiments, in the year 1885, I still held to the old 
view, universally current until now, that smut germs generally could 
penetrate only into the young seedlings in order to appear later as smut 
b^dsiu the full-grown plant, and that, consequently, a penetration of 
the germ into the plant when it had passed the seedling stage was not 
possible. I had not then tried infections in the heart of full-grown 
plants. In the failure of the infections with the corn seedlings I first 
found the suggestion for the latter. Gradually I came to the conviction 
that the view that the fungous germ could penetrate only into the seed¬ 
ling was an embarrassing one ; that the seedling consisted only of the 
young parts of plants, and that, of course, the penetration must occur 
not exclusively in the seedling but also in all places which were in a 
young condition similar to the seedling. This applied, first of all, to the 
growing points, the buds, the heart of the plant which was still grow¬ 
ing and forming new tissues overhead. Here, therefore, the infections 
must be made. These I now prepared for by sowing kernels of corn in 
long beds, in the open air, at the end of April of the following year 
(1886). 
II. In the first half of June, 188G, the maize plants of a long bed 
were abundantly infected in the heart by means of a suitable spraying 
flask. For the most part these plants were about a foot high, and the 
young leaves of the growing point had formed cornets very suitable for 
receiving the infection. The plants remained uncovered, as a period of 
dry weather had set in. The injected fluid containing the sprout germs, 
which at first covered the growing point, was not to be seen on the fol¬ 
lowing days. The leaves of the tip continued to develop during the 
