ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
767 
protoplasm. It is this amoeboid condition showing the plasticity of 
juvenile protoplasm, which makes the author’s observations so inter- 
esting. 
Bacteriological Examination of Drinking Water in Christiania.* — 
Herr L. Schmelck gives in chart form the result of his bacteriological 
examination of the drinking water of Christiania for the years 1888 
and 1889. The chart shows that in May and April the number of 
bacteria found in the water are enormously in excess of what occur at 
other periods of the year. This increase coincides with the time of the 
melting of the snow ; in other words, there is a direct relation between 
the spring melting of the ice and snow and the number of bacteria found 
in running water. The author considers that the explanation of their 
presence is that the bacteria are swept away from the upper layers of 
the surface-earth by the snow-water; a similar result ensues after 
heavy falls of rain. About 30 species of bacteria, some of which were 
invariably present, while others only appeared at certain seasons, and a 
few cropped up occasionally, were isolated from the Christiania water. 
Chemical analyses of this water were made during the same period 
as the bacteriological examination, but no connection between the results 
was observable, except that traces of ammonia were present in the water 
at times when it contained the largest quantity of micro-organisms. 
Germicidal Action of Blood.f — Prof. A. Bonome, in endeavouring to 
ascertain how far experimental conditions altered the value ascribed to 
the results obtained in researches on the germicidal action of the blood, 
made use of pyogenic micrococci and the intravenous injection of water. 
That is, he used pus of various ages and conditions (acute and chronic 
abscesses), and diluted the blood with water by injections into the 
circulation. By using the pure, but old, pus virus (obtained by filtering 
through porcelain), it was found that the virus increased the germicidal 
action of the blood towards Staphylococcus aureus, albus, and citreus , 
but had no influence on the tissues. With fresh pus (acute abscess) the 
results were quite different, and the virus did not increase the germicidal 
efficiency of the blood, and diminished that of the tissues. When 
sterilized virus from cultivations of various pyogenic cells was used, an 
acquired immunity resulted, and this is ascribed to the greater resist- 
ance of the tissue-elements from custom and association. 
With regard to the intravenous injection of water, it is only 
necessary to remark that this procedure considerably diminished the 
germicidal action, but was not able to suspend it altogether. This 
seems to depend on the loss of the saline constituents and the deficiency 
of oxygen. 
Prof. H. Buchner J has long upheld the virtues of the blood-serum as 
a germicide, and recently, in conjunction with F. Voit, G Sittmann, and 
M. Orthenberger, made experiments to show that not only does blood 
possess a germicidal action, but that this action is due, chiefly at least, 
to the serum. The method by which these results are obtained is in prin- 
* Centralbl. f. Bakteriol. u. Parasitenk., viii. (1890) pp. 102-6 (1 fig.). 
f T. c., pp. 199-203, 234-8. 
i Arch. f. Hygiene, x. (1890) pp. 84-173. See Centralbl. f. Bakteriol. u. 
Parasitenk., viii. (1890) p. 183. 
3 h 2 
