274 
SUMMARY OP CURRENT RESEARCHES RELATING TO 
the. hole is filled with inoculated medium, or the medium may be poured 
in first and inoculated afterwards. By stopping the opening with 
paraffin an apparatus for the cultivation of anaerobes is obtained. The 
block is sectioned under alcohol and may be stained with dilute phenol- 
fuchsin. 
Easy Method for Demonstrating Cholera Vibrios in Water.* — 
Dr. S. Pouiklo has frequently adopted the following procedure when 
examining water suspected of containing cholera bacteria. From the 
top of the sample of water one litre is placed in a sterilized flask, and 
10 per cent, sterilized bouillon added. After having been incubated for 
24 hours the scum is examined by the ordinary plate method. If 
large incubators are available two or more litres of water can be used, 
and the chance of discovering the bacilli much enhanced. 
Demonstrating Protozoa and Spirilla in Drinking-water. f— Dr. 
M. W. Beyerinck finds that the “ bacteria-level ” procedure adopted by 
him for describing the respiration figures of micro-organisms is very 
suitable for demonstrating the presence of Protozoa and spirilla in 
drinking-water. In this method a small quantity of nutrient gelatin, 
agar, &c., is placed at the bottom of a test-tube and the latter then filled 
up with the water to be examined. Very favourable conditions for the 
development and growth of micro-organisms are found in the column of 
water exposed to the air on one side, and to an absorbable pabulum on 
the other. Among the organisms isolated by this method are mentioned 
the following: — Oikomonas termo , Spirillum undulata , Colpoda cucullus , 
Cladothrix dichotoma , a Crenothrix., and various Bacteria. 
(4) Staining- and Injecting. 
Staining Nervous Tissue with Methylen-blue.J— Mr. G. H. Parker 
demonstrates the nervous elements of crawfish as follows. Into the 
ventral sinus of the animals 1/10-1/20 ccm. of a 0*2 per cent, aqueous 
solution of methylen-blue are injected and the animal is kept alive for 
about 15 hours. By that time special elements are stained dark blue, 
and in order to fix the colour, the parts are excised and washed with 
physiological salt solution and then immersed in a cold saturated aqueous 
solution of sublimate for about 10 minutes, The water is extracted 
with a mixture of 5 ccm. methylal and 1 grm. sublimate, in which an 
abdominal ganglion is allowed to stay for about 15 minutes. 
In order to extract the sublimate and to replace the methylal by 
xylol the preparation is placed in a mixture of 1 vol. pure methylal, 
1 vol. of the mixture of methylal and sublimate first used, and 2 vols. 
pure xylol. After 10 minutes the preparation is placed in pure xylol, 
wherein it remains for 4-5 days until the methylal is entirely replaced by 
xylol and the last trace of sublimate is extracted. In order to obtain a 
good result the preparation must remain in the xylol for a longish time 
because sublimate is but little soluble in this fluid. When saturated 
with xylol the preparation may be imbedded in xylol-balsam and inspected 
* Wiener Klin. Wochenschr., 1893, No. 14. See Centralbl. f. Bakteriol. u. Para- 
sitenk., xv. (1893) p. 27. 
t Centralbl. f. Bakteriol. u. Parasitenk., xv. (1894) pp. 10-15. 
♦ SB. Gesell. Naturforsch. Freunde zu Berlin, 1892, pp. 97-8. 
