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next 10 days normally and luxuriantly. On the twelfth there appeared 
an etiolation in the heart of the plant, which extended upward as far 
a the leaves had previously been touched by the injected fluid. In the 
blanching leaves, the surface of which was strewn with penetration 
spots, there was an abundant production of mycelium, which had pene¬ 
trated in all directions. In addition, the commencing hypertrophy of 
tissue was already clearly visible iu the attacked and ever-paler appear¬ 
ing parts. After an additional week, in which the grow T th of the 
whole plant, including the parts attacked, had proceeded considerably, 
the cancroid swellings of the smut pustules reached full development 
and a size never before seen. The entire leaves were covered with a 
complete crust of pustule, which in part made them almost unrecog¬ 
nizable; out of all parts of the axis, in fantastic forms like ulcers, the 
great smut swellings grew luxuriantly, so that the plants in their 
entirety were deformed and spoiled—a complete picture of disease. 
Scarcely had the rapidly developed swellings reached full size when 
they lost their white appearance through internal change of color. 
The spore formation quickly included the whole densely interwoven 
mycelial skein inside of the swelling, and the final result was a black 
mass of smut spores inclosed by the external tissue layers of the host 
plant, e. g., of the pustule.* 
Of all the plants which were infected, i. e ., more than a hundred, none 
remained sound after 4 weeks. The smaller they were at the time of 
infection, the more they suffered. The extension of the young axis, which 
was disturbed by the formation of smut and the accompanying hypertro¬ 
phy of tissue, was afterward completed. Whole plants were wasted and 
distorted by the fungus into miserable objects. They lay in part upon 
the earth and perished without exception. On the larger plants the 
formation of pustules was localized upon the upper parts, the only ones 
attacked. The lower sound leaves continued to nourish the plants and 
they did not die. In only twelve of these plants did the injected 
fluid reach as far as, or penetrate into, the nascent staminate inflores¬ 
cence. To the extent-that this happened the parts soon became 
smutty, sometimes the tips only, and again the lower portions. The 
glumes and the filaments swelled more than fifty-fold, and in isolated 
cases became tumors which, by their weight, afterwards bent down the 
whole panicle. The long series of charts which I have hung up, and 
which were drawn by my young friend and associate, Dr. Istvanffi, of 
Klauseuburg, will serve to illustrate the most striking cases from these 
series of experiments.t In the upper part of one of the pictures, in the 
* Through this pathological picture of the cancerous tumors on the maize plant we 
arrive involuntarily at the notion of what the symptoms would be if the smut spores 
were not black, and were not produced in such masses as happen iu the maize, and if 
the substratum were not a vegetable, but an animal organism. 
t These charts, and many others illustrating the life history of smuts, may be found 
in Dr. Brefeld’s Heftcn v and x, to which he desires me to call attention. These are 
published by Arthur Felix, Leipsic, Germany. Part x, giving in extenso the results 
here summarized, is now passing through the press.—T r. 
