796 The American Naturalist. [October, 
THE BACTERIAL DISEASES OF PLANTS: 
A CRITICAL REVIEW OF THE PRESENT STATE OF 
OUR KNOWLEDGE. 
By Erwin F. SMITE. 
(Continued from p. 731) 
III. 
Nore.—A second note by Dr. Sorauer on the Bacteriosis of Fodder 
Beets adds a number of interesting items. This is entitled (24a) Die 
Gummikrankheit bei Runkelruben etc. It was published in Jahrb. d. 
Deutschen Landwirtschafts- Gesellschaft. Bd. 7, Berlin, 1892, Second = 
pp. 206, 207, and was republished verbatim in Zeitschr. f. Pflan. 
2Bd. 5Heft, 1892, pp. 280-281. The following abstract should one 
fore be read in connection with the Remark on p. 723 from which place 
the reference was inadvertently omitted. 
Samples of the diseased beets were received from Vukovar in October, 
1890 and in February, 1891. With the first specimens came the state- 
ment that one half of the crop was affected. The beets were drilled 
early in April and the weather was favorable until the middle of June ; 
then hot and dry weather set in, continuing until harvest time in the 
middle of October. During all this time there was only one rain. The 
beets suffered severely from the heat and drouth, losing all their outer 
leaves and pushing new ones toward the end of September. At harvest 
time the disease was found more or less developed in such plants as 
showed wilted heart leaves. The blackening of the roots, a blue black, 
began at the lower extremity and continued upward after the roots were 
stored. The flesh of the root appeared to be uniformly blackened at the 
root tip, and from this part the discoloration radiated upward into the 
sound part so that at last it was noticeable only in the regions of the 
vascular bundles as brown stripes and rings, the rest of the flesh being 
white. On making a cross section of the beet root a drop of gum some- 
times exuded within a few minutes from isolated points of the browned 
vascular strand. The affected beets became flabby and shriveled length- 
wise and in places showed a sticky sweat or an abundant exudation of 
gummy masses through the uninjured surface, forming a lacquer-like 
covering. In bad cases gum cavities appeared in the flesh from solution 
of the tissues. The diseased beets contained a strikingly large amount 
s 
