726 The American Naturalist. [September, 
“A section from any part of a diseased root, under a magni- 
fication of four or five hundred diameters, shows the presence 
of great’ numbers of bacteria.” “These bacterial parasites 
of the beet are not few, or difficult of detection ; but occur in 
great numbers in every cell of the plant, and are conspicuous 
under the microscope without staining or other special treat- 
ment. The more pronounced the disease the greater the num- 
ber of bacteria. They are most abundant in the large, loose- 
celled tissue, lying between the fibrous rings of the root and 
in the similar tissue of the veins and midrib of the leaf. This 
tissue consists of parenchyma, in which the protoplasm lines 
the walls of the cells and stretches across in strings from side 
to side. The bacteria are largely imbedded in or attached to 
the protoplasm, but also occur in the cell sap, sometimes in 
large numbers. While the bacteria are most abundant and 
conspicuous in the colorless parenchyma, they also occur in the 
cells of the fibro-vascular bundles, and in the green cells of the 
leaf; in fact, as has already been said, in all parts of the plant.” 
(5) Direct Infection Experiments.—No direct inoculation, or 
grafting of diseased roots upon healthy ones, appears to have 
been tried. 
(II) THE PARASITE. Organism not named. 
1. Pathogenesis. 
(A) Yes. 
(B) Yes. Easily isolated. Plate method. From the deeper 
tissues of the roots only one form of microbe is ob- 
tained. 
(C) No, or yes, doubtfully. “Inoculation with pure cul- 
tures into the beet root has been attempted, and re- 
sults appear to show that the disease was transmitted ; 
but the trials were few, and we desire to repeat them 
before further discussing this part of the subject.” 
(D) No. 
Conclusion.—Pathogenic nature not established. 
2. Morphology. 
(1) Shape, size, etc—The bacteria are all of one shape and 
appearance. They are nearly twice as long as broad, small, 
