180 BOTANICAL GAZETTE [SEPTEMBER 
of Europe. The points of similarity will be noted in the follow | 
ing description of the disease and of the germ by whichitispm — 
duced. | 
GENERAL DESCRIPTION OF THE DISEASE. 
About the middle of September 1896 several diseased bees 
were found in the field of cultivated beets on the grounds of the 
Purdue Experiment Station. The disease attacks the whole 
beet plant, causing a peculiar appearance of the leaves, so that 
with a little practice the diseased beets can be distinguished — 
readily from the healthy ones as they grow in the field. The 
outer, older leaves soon die away, and the intermediate and 
heart leaves are left wrinkled, curled, rather flabby than turges 
cent, and of a yellowish-green color. This wrinkled appearaice 
is caused by blister-like patches being formed between the | 
veins of the leaf, and the whole has been described as resembling 
a Savoy cabbage leaf. See photographs of leaves, plate XVI, 
also photographs of diseased beest, p/ates XVII, and XVII # 
The appearance of the exterior of a beet root when disease 
is not materially different from that of the healthy beet. Kk | 
perhaps not quite as brittle. A decisive test for the wee 
found in the appearance that the root shows when ae 
The fibrovascular bundles appear as dark rings in the oe fai : 
They grow almost black after being exposed to the air forST 
minutes. These rings are quite distinct from the cream col 
fibrovascular bundles of healthy beets (plate XIX). t og 
In 1896 in a field of beets covering an area of mee 
acre and containing approximately 130,000 beets, oi ss 
diseased and several slightly affected ones were foul 
was a smaller number than had been found on the ge te 
in previous” years, and can perhaps be accounted < 
climatic conditions being so favorable to plant BF : The 
preceding summer, there being an abundance of me 
number of diseased beets increased, however, beige! 
time. geased the 
Frost seems to be much more injurious to the di 
