ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
85 
embryo, used freshly fertilized hen’s eggs, which were artifically incu- 
bated in the usual manner. When development had proceeded for 
various lengths of time, a small piece of shell and of the shell-membrane 
was removed, and the embryo inoculated with various micro-organisms ; 
the aperture thus made was closed again, and sealed down with wax and 
a cover-glass. The micro-organisms used were saprophytes, e. g. pink 
yeast, Staphylococcus albus, Micrococcus prodigiosus , Bacterium vio- 
laceum , and others. About two hundred eggs were inoculated, and in 
all cases development was stopped, and this result was usually accom- 
panied by decomposition. The author comes to the conclusion that the 
transmission of infection to the embryo of birds takes place in a manner 
different from that observed in Mammalia. 
Water Bacteria and their Examination.* — Herr A. Lustig has re- 
cently published a work on the “ diagnosis of water bacteria, with direc- 
tions for their bacteriological and microscopical examination.” In dealing 
with these micro-organisms, the author first treats of those pathogenic to 
man, next those that are noxious to animals, and thirdly those which 
are harmless ; the series is further subdivided into cocci, bacilli, and 
spirilla. Although there is a copious literature of water bacteria, yet, 
as it is much scattered, this work, which brings together the descrip- 
tions and results of many writers, cannot fail to be useful, more especially 
as the diagnosis tables are accompanied by practical directions for the 
bacteriological investigation of water. 
Action of Products secreted by Pathogenic Microbes.! — The work 
of M. Bouchard is in the first place a review of what is at present known 
as to the action of bacterial secreta on micro-organisms and on animal 
organisms ; and secondly, a record of the author’s own views. It will be 
sufficient here to allude to the various theories of immunity, which in 
this book are discussed at length. According to the author, acquired 
immunity depends on two factors : — first, an increased germicidal 
influence of the animal fluids ; and secondly, an increased inclination of 
the cells to act as phagocytes. If, therefore, the leucocytes acquire 
an increased tolerance for the bacterial virus, and at the same time 
the germicidal power of the animal fluids is augmented, the organism 
may then be said to have obtained an acquired immunity for the disease 
in question. 
Fraenkel’s Bacteriology.! — The third edition of Fraenkel’s Out- 
lines of Bacteriology has just appeared. As far as the lines on which it 
was originally constructed are concerned, it remains the same, differing 
from its predecessors chiefly in the additional facts which it records. 
Thus, several kinds of bacteria are described in the special part for the 
first time, the position of some is altered, e. g. cholera bacilli are now 
ignored in favour of the term vibrio. This part is further expanded by the 
additional space given to the bacteriological examination of air and water. 
* ‘ Diagnostica dei batferi delle acqne con una guida alle ricerche batteriologiche 
e microscopiche,’ Torino, 1890, 8vo, 121 pp. See Centralbl. f. Bakteriol. u. Para- 
sitenk., viii. (1890) pp. 594-5. 
+ ‘ Actions des produits secretes par les microbes pathogenes/ Paris, 1890. See 
Centralbl. f. Bakteriol. u. Parasitenk., viii. (1890) pp. 433-5. 
X C. Fraenkel, 4 Grundriss der Bakterienkunde,’ 3rd ed., 1890, 515 pp. See 
Centralbl. f. Bakteriol. u. Parasitenk., viii. (1890) p. 621. 
