ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
127 
of tlie thermostat gets hotter the ether expands in the reservoir C, drives 
the water on to the mercury in h , and this ascending into the Y-shaped 
tube// /, cuts off the hot stream from the boiler. Numerous and com- 
plicated details are given for the avoidance of air-bubbles, but for this the 
original must be consulted. 
Cultivating Ascospores.* — Dr. H. Wichmann says that he has culti- 
vated ascospores on firebrick blocks since 1888. They are shaped like 
a truncated cone, the upper surface having a diameter of 55 mm., the 
lower 65 mm., and the height being 30 mm. The broader surface is 
somewhat hollowed out. The blocks are cleaned by first scrubbing and 
drying them, after which they are sterilized by exposure for two hours 
to a dry heat at 150°. During the sterilizing they are placed inside a 
glass vessel, the lid of which is left loose, the whole contrivance being 
wrapped up in filter-paper. 
The conical form of these blocks prevents the cultivation surface 
from coming in contact with the side of the containing glass vessel, and 
thus prevents the condensation water from damaging the cultivation. 
Cultivating Vibrios.f — In his experiments with water vibrios Dr. J. 
Sanarelli used large quantities of water for isolating these organisms. 
Usually 200 ccm. of liquid were poured into a sterilized flask sufficiently 
large for a large surface of water to be in contact with air, and then 
8 ccm. of the following mixture were added : — Gelatin 20 ; pepton 10 ; 
sodium chloride 10 ; potassium nitrate 1. 
This mixture, made in advance, is kept in sterilized tubes, and when 
dissolved up for cultivation purposes has the following composition : — 
Gelatin 2 ; pepton 1 ; sodium chloride 1 ; potassium nitrate 0*1; 
water 100. In this medium vibrios thrive excellently well when incu- 
bated at 37°, and in twelve hours form a surface scum, from which 
loopfuls may be removed for microscopical or further bacteriological 
experiments. In the latter case the loopful should be plunged into a 
tube full of sterilized water, and from this dilution gelatin plates may 
be made. In this way perfectly pure cultivations are easily obtained. 
The author further notes that the presence of too much albuminoid 
matter, e. g. meat broth, more especially with agar, is detrimental to the 
development of vibrios, and replaces it with distilled water. By this 
substitution is obtained a medium of exceptional transparency, which 
is peculiarly adapted for the cultivation of all kinds of vibrios at incu- 
bation temperatures ; it has also been employed for differential diagnosis 
of various species of vibrios. 
Cultivation Media for Anaerobic Bacteria.; — Prof. J+\ G. Novy 
recommends the following media, all of which he has used with success, 
for the cultivation of anaerobic bacteria : — 
(1) Meat broth, to which are added 1/2 per cent, sodium chloride, 
2 per cent, grape-sugar, and 2 per cent, pepton. (2) The foregoing, 
plus the addition of 2 per cent, gelatin. (3) 10-15 per cent, gelatin to 
which salt, pepton, and grape-sugar have been added as above. (4) 
1/2-2 per cent, agar, with the addition of salt, pepton, and grape-sugar 
* Centralbl. f. Bakteriol. u. Parasitenk., xiv. (1893) pp. 62-3. 
f Annales last Pasteur, vii. (1893) pp. 700-2. 
% Centralbl. f. Bakteriol. u. Parasitenk., xiv. (1893) pp. 595-9. 
