ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
239 
in a delicate sheath. Cultivated on gelatin at 15° C. they form white 
colonies for the first three days, but on the fourth a blue pigment 
appears at the margin of deep-lying colonies, and at the edge of the 
superficial ones. The pigment, which is in very fine granules, does not 
penetrate the gelatin. The bacillus is aerobic and does not liquefy 
gelatin. When cultivated in meat-brotli it did not thrive, and 
no pigment was formed, and incubation temperatures either diminished 
or prevented growth. 
On agar there developes an indigo-blue deposit, which appears as a 
coloured band from 2-3 mm. wide around the edge, and resembling the 
iridescent shimmer of a saturated solution of gentian-violet. Potato 
cultivations have the same appearance as those on agir, but the pigment 
only appears with an acid reaction of the potato. If this be alkaline 
there developes only a dirty green tuft, but without any detectable mor- 
phological difference of the bacilli. 
Neither spore-formation nor filamentous outgrowths were observed. 
When distilled water was inoculated with bacillous material, a 
distinct milky clouding was observable in twenty-four hours, and a 
dark-blue, almost black, granular sediment was formed on the bottom of 
the vessel. The indigo-blue pigment was formed in the various media 
even in the dark. 
The pigment is insoluble in hot and cold water, absolute alcohol, and 
in a mixture of equal parts of ether and alcohol, is slightly soluble in 
caustic potash, in hot sulphuric acid, and in cold hydrochloric acid. 
Peculiar Disease of Bread.* — In the interior of loaves of Graham 
bread, one or more patches of variable size, forming brownish, sticky, 
viscid masses with a peculiar smell, are sometimes found. This degene- 
ration has been found by Herren Kratschmer and Niemilowicz to be due 
to the action of Bacillus mesentericus vulgatus , which, when inoculated on 
healthy bread, infects it as soon as it shows a slightly alkaline reaction. 
It is therefore inadvisable to bake large loaves, as the interior of 
the loaves is not sufficiently heated to kill the germs. 
Growth of Bacillus of Symptomatic Anthrax on solid nutrient 
media.j — Mr. S. Kitasato has obtained anaerobic cultivations of “Rausch- 
brand” bacillus on agar and gelatin to which sugar, glycerin, and reducing 
media had been added. In solid media the bacilli retained their 
virulence, which was not the case in cultivations of guinea-p ; g broth. 
The most favourable temperature was from 36°-38°. Grown in gelatin 
under hydrogen, spheroidal colonies are formed which liquefy their 
adjacent medium. The baeilli are straight rods with rounded ends and 
possessing characteristic movements. In gelatin at the ordinary 
temperature they form spores only slowly, but quite quickly at incuba- 
tion temperatures. The spores are oval, and the sporogenous bacilli 
are immobile. The spores are resistant to drying for several months ; 
heating to 80° for one hour does not kill them. 
Contrary to the statement of Metschnikoff, the author finds that 
* Wiener Klin. Wochenschr., 1890, No. 30. See Bot. Centralbl., xliii. (1890) 
pp. 401-2. 
f Zeitschr. f. Hygiene, viii. p. 55. See Centralbl. f. Bakteriol. u. Parasitenk., 
viii. (1890) pp. 15-6. 
