ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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limate, and again alcohol. An opening was next made at one end with 
a red-hot iron and the egg inverted over a sterilized test-tube. Another 
opening was then made at the opposite end and the contents of tho egg 
evacuated into the test-tube. The medium was immediately inoculated 
and the tube closed with cotton-wool. All the tubes were kept at the 
room-temperature, and in all a copious growth was observed. Thus 
cultivated, the micro-organisms could be successfully transferred to the 
ordinary media. 
Egg-yolk Medium for Cultivating Influenza Bacillus.* — Dr. M. 
Nastiukow prepares an artificial medium in which influenza bacilli thrive 
wonderfully and can be cultivated through several generations. One litre 
of distilled water is made alkaline by mixing with 5 grm. of 10 per cent, 
solution of caustic soda, and in this are dissolved 100 ccm. of yolk of 
egg. This is the liquid medium, and to obtain a solid one 15-25 grm. 
agar are dissolved in one litre of the yolk solution by boiling, and then 
passed through a Plantamur’s filter. The media are sterilized in Koch’s 
steam sterilizer. The cultivations were made from saliva, and on plates 
formed small round transparent yellowish colonies. In the liquid 
medium, after an incubation of twenty-four hours, little white wedge- 
shaped lumps sank to the bottom of the test-tube. 
Blood-Serum as Diagnostic Cultivation Medium for the Cholera 
Vibrio, f— The method devised by Dr. A. Maassen for diagnosing cholera 
bacilli depends on the observation that these organisms flourish freely 
on solid serum, and that they have the power of liquefying the medium, 
a property in which they excel all other bacteria found in faeces or in 
the contents of the alimentary tract. 
The procedure is very simple, and merely consists in smearing some 
of the soft portions of the dejecta or flakes, &c., with a platinum instru- 
ment on the serum surface of several tubes. When cholera vibrios are 
present the inoculated places seem as if they had been eroded in from 
6-12 or at latest in 20 hours. From the holes or fissures thus formed 
cholera vibrios in almost pure cultivations may be fished out. The 
proliferation of the vibrios may often be demonstrated even before the 
softening and liquefaction is apparent (3-4 hours). In many cases it 
may be necessary to inoculate from the first to a second serum surface 
or a pepton-salt solution. 
For the demonstration of cholera in water the blood-serum may be 
used directly after the preliminary pepton-salt solution. Such experi- 
ments have shown that spirilla and vibrios which do not grow on other 
media thrive in this solid serum, and can be easily obtained in pure 
cultivations. The advantages of oblique blood-serum have been found 
to be that in non-diarrhoeic stools which contain only few comma- 
bacilli more material can be sown than in pepton-tubes. The lique- 
faction of the serum within 24 hours renders it probable that cholera 
vibrios are present, and if this indication be absent these organisms are 
not present. The cholera vibrios are not so easily overgrown by other 
bacteria as in other media. 
* Wratsch, 1893, Nos. 30, 32, 33. See Centralbl. f. Bakteriol. u. Parasitenk., 
xiv. (1893) pp. 815-0. 
f Arbeiten a. d. Kaiserl. Gesnndheitsamte, 1894, pp. 122-G. See Centralbl. f. 
Bakteriol. u. Parasitenk., xy. (1894) pp. 251-2. 
