718 The American Naturalist. (September, 
parenchyma contained tiny roundish or-ellipsoidal shining 
bodies, which were of various sizes, and either scattered about 
in the cells pr united into groups. The individual particles 
showed not rarely a tremulous motion. When such a thin sec- 
tion was fixed to a cover glass by passing it three times through 
the flame, and was then stained with gentian violet, these 
bodies became a beautiful blue, and their bacterium-like form 
could be made out more clearly. In the parts of the root 
which had already become slimy great numbers of bacteria 
were to be seen in the gum-like fluid, together with loosened 
cells, plasma, and fragments of cell membranes. 
(5) Direct Infection Experiments—When a little of the soft, 
slimy mass was lifted on a sterile platinum needle and spread 
on a sterile [steamed ?] section taken from an apparently sound 
beet, the surface of the latter was covered within forty-eight 
hours with a slimy, brown, gum-like, acid layer, which con- 
sisted of a mass of those bacteria previously found in the dis- 
eased beets. Sections cut out of diseased beets with sterile 
knives and placed on fresh, unsterilized sections from sound 
beets, and kept in a moist chamber at 24° C., caused the latter 
to become affected. The infected spots browned and softened, 
and in the tissues bacteria appeared, which were just like those 
occurring in the diseased beets. A slimy layer also formed on 
the sterile cut surface of carrots when a slight quantity of the 
slimy ooze from the beets was spread over it. 
“This preliminary investigation indicated that most likely 
in this case we have to do with a disease caused by bacteria. 
Positive proof, however, is not thereby afforded. To accomp- 
lish this experimentally it is absolutely necessary to isolate the 
bacteria occurring in the diseased beets, to cultivate them pure, 
and then to inoculate the pure cultures into sound living beets. 
If then asa result of the infection the previously healthy beet 
should become diseased with the before-mentioned symptoms, 
and the originally inoculated bacteria should appear once more 
in the tissues, then there would be no doubt about this being 
a bacteriosis of the beet.’ 
Clearly this man knew exactly. what he had to do. 
