1896.] The Bacterial Diseases of Plants : 797 
of grape sugar. This was determined by use of Barfold’s reagent. Two 
milch cows fed on these roots died the second day. The symptoms were 
bloating, pain in the abdomen, obstinate constipation, and the prolonged 
vomiting of a tough yellow slime. In both cases pieces of the diseased 
beets were found in the first stomach along with other food, and no other 
reason for death was apparent. These beets (four varieties) were grown 
on a porous clay soil containing 5% lime and 8% humus. The soil- 
water level was 16 meters from the surface. The field had been very 
heavily dunged with stable manure. 
Il. THE HYACINTH (HYACINTHUS ORIENTALIS L). 
1. THE YELLOW DISEASE (1883). 
(I) THE DISEASE. 
(1) Author, Title of Paper, Place of Publication—This disease 
was described by Dr. J. H. Wakker, as a result of investiga- 
tions begun in the fall of 1881 at the request of the Algemeene 
Vereeniging voor Bloembollencultur te Haarlem, and was 
carried on in the laboratories of the University of Amsterdam. 
The first brief account appeared in 1883, in Botanisches 
Centralblatt (Bd. XIV, pp. 315-316) and forms part of a (30) 
Vorläufige Mittheilungen über Hyacinthenkrankheiten. The 
following year a more extended account was published in 
Dutch, (31) Het geel-of nieuwziek der Hyacinthen veroorzaakt 
door Bacterium Hyacinthi Wakker (Onderzoek der Ziekten van 
Hyacinthen, en andere bol-en knolgewassen. Verslag over het jaar 
1883. Haarlem, August, 1884. 8vo, pp. 4-13, one colored 
plate). Two additional papers were published in Dutch, con- 
tinuing and concluding the one above mentioned, (32) Onder- 
zoek etc., Verslag over het jaar 1884. Haarlem, May, 1885, 
8vo, pp. 1-11, and (33) Onderzoek ete., Verslag over het jaar 1885. 
Haarlem, May 1887, 8vo, pp. 1-5, and 27 to 37). These are 
the important papers to read and the ones which have mostly 
escaped mention. Finally, six years after the commencement 
of the investigation, Dr. Wakker published a fifth paper, 
entitled (34) Contributions à la pathologie végétale: I. La 
maladie du jaune, ou maladie nouvelle des jacinthes, causée 
par le Bacterium Hyacinthi (Archives néerlandaises d. Sci. ex. et 
nat., tome XXIII, 1889, pp. 1-25, pl. I). This paper is merely 
56 
