ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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are believed by the author to be an early stage of spore-formation. The 
author regards potato as being a superior cultivation medium for tubercle 
bacilli to glycerin agar, and in conclusion expresses the hope that, through 
vegetable cultivations, an attenuated virus, suitable for vaccination 
purposes, may eventually be procured. He states that the virulence of 
the tubercle is altered when cultivated on potato, and that this alteration 
increases with age. 
Impervious Self-acting Self-regulating Stopper for Sterilizing 
Purposes.* — Dr. Pannwitz says that the rubber caps used for bacterio- 
logical purposes may also be used as stoppers for vessels when they are 
being sterilized. It is suggested that the lip of the tube, &c., should be 
broad. The rubber cap is perforated with a red-hot platinum wire at 
some part where it rests against the edge. The wire-made opening is of 
course under these circumstances quite impassable, but when the tubes 
or vessels are incubated, the pressure inside rises and causes the rubber 
cap to bulge outwards and so to open up the aperture. The author 
states that this device is quite effective, and that he has used it for 
some time for all kinds of sterilizing purposes. It certainly has the 
merit ef extreme simplicity. 
Improvising Bacteriological Apparatus.! — Prof, von Esmarch calls 
attention to the fact that bacteriological apparatus is often not at hand 
when most needed for diagnostic purposes, e. g. in an out-of-the-way place 
where cholera is suspected to have broken out, and under these circum- 
stances makeshifts must be accepted. Yet nothing can supply the place 
of a Microscope and suitable accessories, and if these be absent almost all 
is lost. But other orthodox appliances can be done without and their 
place supplied by some temporary arrangement ; for example, an incuba- 
tor may be made of a saucepan in which is placed one kilo of acetate of 
soda dissolved in a little water, and then heated up to 60°. If the 
saucepan be covered up the vessel will retain sufficient heat for incuba- 
tion purposes for 24 hours. Or if the vessel be filled with water at 37° 
a night-light placed underneath will maintain the temperature for 
practical purposes at the proper level. 
Rapid Demonstration of Cholera Bacilli in Water and Faeces.^ — 
Dr. Schill says that old bouillon cultivations of cholera bacilli, which 
have been sterilized by boiling, form a most suitable basis for starting 
cholera cultures for diagnostic purposes. If the culture be some months 
old then 2-3 hours in the incubator after inoculation with faeces or 
water is quite sufficient for the purpose ; if, however, the cholera 
bouillon be young then it may be necessary to incubate for 24 hours. 
Plate cultivations are next to be made of meat-pepton-gelatin and agar, 
the former kept at 20°, the latter incubated at 37°. At the same time 
it is advisable to make gelatin puncture cultures to see the characteristic 
liquefaction. A few loopfuls of the first tubes should be transferred to 
alkaline pepton water (1 per cent, pepton, 0*5 per cent, sodium chloride, 
1 per cent, crystallized soda) to test for cholera red reaction which will, 
* Centralbl. f. Bakteriol. u. Parasitenk., xiii. (1893) pp. 754-5. 
t Hygienische Rundschau, 1892, p. 653. See Centralbl. f. Bakteriol. u. Para- 
sitenk., xiii. (1893) p. 628. 
: Centralbl. f. Bakteriol. u. Parasitenk., xiii. (1893) pp. 750-2. 
