OUR BOOK SHELF. 165 
OUR BOOK SHELF. 
A Manual of the Infusoria. W. SAVILLE KENT, F.LS., F.Z.S., 
F.R.M.S. London: David Bogue. 1880. Part IV., pp. 433- 
575, with 8 plates. 
The fourth part of this admirable work ends the first volume 
and commences the second. As an appendix to the first, our 
author takes up the gauntlet which Dr. Cooke threw down, and re- 
capitulates much of what he has stated in the April number of the 
“Popular Science Review.” He has experimented with the Myxo- 
gaster discovered in Cheshire by Mr. Thos. Brittain, formerly called 
Badhamia capsulifer, by Dr. Cocke, but now Physarum tussilaginis 
(see THE NORTHERN MICROSCOPIST, p. 142) and has watched the 
development of its spores. For all the details we must refer our 
readers to the original paper, which will be found of a most inter- 
esting character, and the question is one of such vital importance 
and interest, that there should be no difficulty in securing workers 
in this field. 
Chapter VIII. contains a systematic description of the Infusoria- 
ciliata, and here also we find descriptions of the many organisms 
which are too often overlooked on account of their frequent re- 
currence. The genus Parameecium is well described, and all the 
observations of the different species may easily be followed by the 
student. The same may be said of such genera as Coleps, Bur- 
saria, Nassula, and others. 
The pages treating on Asthmatos ciliaris will probably be read 
with interest by the medical practitioner, who, not thoroughly 
wedded to the pollen theory of the cause of “‘ Hay Fever,” will find 
some food for reflection on pp. 466 and 467 and future study. 
The character of the work is well maintained through these four 
parts, there is scarcely a page which does not contain matter of 
more than common interest. 
Angular Aperture of Microscope Objectives. Gro. E, BLAcKHAM, 
M.D., F.R.M.S. New York: The Industrial Publishing Co, 1880, 
21 pp. and 18 plates. 
This is a reprint in book form of a paper read before the Micros- 
copical Congress at Indianopolis, on the 13th of August, 1878. 
In his preface the author makes apology for the omission of mathe- 
matical formula, stating that such would either be uninteresting or 
unintelligible to a large number of microscope users, who are 
nevertheless desirous of information upon the subject of Angular 
Aperture. 
