40 The American Naturalist. [January, 
apparently quite careful microscopic examinations, but no — 
pure cultures. His attemps at direct infections yielded nega- 
tive results and he says that the bacteria do not attack sound 
well ripened bulbs under normal meteorological conditions. 
The fungus, Hypomyces hyacinthi Sorauer, was closely associated 
with this rot but is believed to be only a secondary trouble in 
as much as the bacteria were sometimes found in the affected — 
tissues where no mycelium could be detected. The fungus — 
may however spread the disease by acting as a carrier of the — 
microorganisms. The latter consisted of coccus forms and 3 
rods, and were identified, in part, as Clostridium butyricum — 
(Bacillus amylobacter), apparently on no better grounds than the 
microscopic appearances and a bad smell supposed to be due 
to butyric acid. This work was done fifteen years ago and : 
now has little other than a historic value. The following are — 
Dr. Sorauer’s papers: 
(36) Der weisse Rotz der Hyacinthenzwiebeln, Deutscher — 
Garten, 1881, pp. 198, (not seen), and (37) Der weisse Rota — 
(Bacteriosis) der Hyacinthenzwiebeln, Sorauer, Handbuch der — 
Phlanzenkrankheiten, 2nd. ed., part II, pp. 95-102, with one plate — 
(devoted exclusively to the Hypomyces), Berlin, 1886. 
Concerning the “white rot” of the Netherlands, Wakker 
states distinctly that it is not a parasitic disease, and seems to 
have proved that it does not attack sound bulbs but only such 
as have been weakened by anonparasiticgummosis. Whether 
this is always the case may, perhaps, be regarded as doubtful, 
in as much as Dr. Wakker’s inoculation experiments were not 
very numerous. This white rot is a slimy, and often foamy, 
stinking, bacterial decay to which gummosed bulbs are fre- 
quently subject in rainy, warm weather, particularly after the _ 
bulbs are dug and placed in silos in the earth to undergo & 
ripening process. The disease may also appear afterwards in 
rooms where the bulbs are spread out to dry. The whole or : 
only a part of a bulb may be attacked according as the whole | 
or only a part is gummy. The diseased parts are soft and 
white and look as if boiled. Dr. Wakker’s views may be 
found in (34) and in (38) Contributions à la pathologie végétale. — 
VI. Nouvelles recherches sur la gommose des Jacinthes w 
