136 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Tlie spheres can only be used when the object-stage of the Microscope 
possesses an opening suitable in size for their reception. Even whore 
this is the case, the displacement of the spheres is not so easy as with 
the ordinary object-holders. The last two defects, however, may be 
remedied by the use of a metal plate having a suitable opening in the 
centre and provided with a rectangular screw-motion. 
The use of the Abbe illuminating apparatus with the spheres is 
impossible, and this defect is not adequately remedied by filling the 
spheres with a strongly refracting liquid. 
Altogether the author is not inclined to recommend the spheres in 
their present form for general use, although he does not deny that, if 
properly modified, they might be of good service in many cases. 
(6) Miscellaneous. 
Atlas of the Clinical Microscopy of the Blood.* — The object of 
Rieder’s Atlas is to present in a few plates the numerous deteriorations 
in the histological characters of the blood for clinical purposes. The 
text is very condensed and serves merely for the explanation of the plates. 
All the illustrations are from original drawings, chiefly from stained 
preparations, though a few are uncoloured. The introduction gives the 
methods for the clinico-microscopical examination of the blood and 
describes the way to obtain a drop of blood, the fixation of dry prepara- 
tions, eosin-hmmatoxylin staining, the demonstration of the nuclear 
structure of leucocytes, Ehrlich’s granules, the blood-plates, the amoeboid 
movement of leucocytes, and a short recital of the course of clinical 
blood-examination . 
The illustrations are well executed ; the magnifications are 300, 400, 
and 1100, except three in which 1600 has been used for showing 
myelsemia and malaria plasmodia. 
It would have added to the value of the work if th ere were a table of 
contents or an index. 
Diagnosis of Water Bacteria.f — The second edition of this work by 
Dr. A. Lustig is published in Italian and German. It deals with water 
bacteria and pathogenic bacteria found in water, and describes 181 
6pecies. The first part deals with bacteria pathogenic to man, the 
second with those pathogenic to animals, and the third with non-patho- 
genic bacteria. The third group is subdivided into (a) Micrococci, 
( b ) Bacilli, (c) Spirilla, (d) Schizomycetes of different developmental 
forms. 
Micrococci and bacilli are further distinguished according as they 
liquefy gelatin or not. In each division the bacteria discussed therein 
are fully described in reference to form, arrangement, mobility, spore- 
formation, and development in different media. The diagnoses are in 
tabular form and resemble in this respect Eisenberg’s tables, though the 
arrangement is different and less clear. The greatest share is devoted 
to bacilli found in water, yet it should be noted that the author’s descrip- 
tion of a bacillus does not accord with de Bary’s conception. Of 
* Leipzig, 1893, 12 pis. and 48 figs. See Centralbl. f. Bakteriol. u. Parasitenk., 
xiv. (1893) p. 208. 
f Jena and Tuna, 1893, 128 pp. See Bot. Centralbl., liv. (1893) p. 335. 
