ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
581 
bacillus in cider, finds that this organism is destroyed in from 2 to 18 
hours after the liquid has been infected. This destruction is due to the 
acidity of the cider, provided that there are at least 2 grin, of malic acid 
per thousand. If the acidity be 0*8-1 per thousand, the organism may 
exist in malic acid for 3 or 4 days, and more than 20 if it be neuter. 
As cider usually possesses an acidity over 2 per thousand, the typhoid 
bacillus cannot live therein longer than 18 hours. If, however, cider 
be diluted with typhoid-infected water, this beverage may become the 
means of imparting the malady if drunk during the first day. 
Bacteria of Sorghum Blight.* — M. F. F. Bruyning jun. describes 
two new bacteria which he has discovered in blighted sorghum. 
B. ruber ovatus sp. n. is somewhat oval in shape, 0*9-1 *2 fx long by 
0*7-0 *8 fx broad, sometimes in pairs or triplets. It is aerobic and does 
not form spores. It is slowly decolorised by Gram’s method. There 
are indications of a capsule. The optimum temperature is 20° C. On 
potato the colour of the growth is bright red or vermilion. Growth 
in bouillon is slow, the medium becoming somewhat opalescent and a 
scanty colourless sediment being deposited. Gelatin is not liquefied, and 
litmus-gelatin remains unaltered. 
J\I. aurantiacus sorgbi sp. n. is round to oval in shape, with a dia- 
meter of 0 • 7-0 * 9 [x. It forms chains. On potato the growth soon 
assumes a bright yellow colour. Milk is coagulated in about seven days. 
Bouillon soon becomes turbid. All the substrata sooner or later present 
an acid reaction. On gelatin the growth is yellow, and the medium is 
not liquefied. The micrococcus is aerobic, but has some tendency to 
potential anaerobiosis. 
The pigment, which is easily obtained from the diseased plant, is 
extremely soluble in strong alcohol. When dried it is of a dark brown 
hue, and is found to possess powerful staining qualities. Silk and wool 
are easily “fast” dyed by dilute spirituous solutions. The author 
dilates freely on the numerous properties of this pigment, and discusses 
the differences between it and other bacterial pigments. 
The pigment of M. aurantiacus sorghi is soluble in weak spirit. 
Sporicidal Action of Normal Rabbit Serum. t — From an experi- 
mental study on immunity carried out through the agency of B. subtilis 
and rabbits, Dr. Podbelsky concludes that the spores of B. subtilis are 
killed by normal rabbit serum in vitro. This sporicidal property ap- 
pears to be imparted from substances derived from leucocytes. Neither 
oedema-fluid nor aqueous humour prevents the development of spores 
nor kills the bacilli. The action of serum rich in leucocytes approaches 
that of blood-serum. Substances in the blood plasma which are capable 
of traversing reed-membranes do not prevent the development of spores, 
and do not kill the bacilli in the body of the living rabbit. Spores of 
B. subtilis introduced into any part of the rabbit are incorporated by 
leucocytes, and their development is arrested. By careful selection a race 
was obtained, the spores of which were able to develop in normal serum, 
and also when injected into the body. The bacilli arising from these 
spores were, however, incorporated and digested by the leucocytes. 
* Archiv. Ne'erland. Sci. Exact, et Nat., ser. ii., i. (1898) pp. 297-330 (2 pis ). 
f Ann. Inst. Pasteur, xii. (189S) pp. 427-46. 
2 r 2 
