487 
1882.] Analyses of Books . 
Applied either in the form of vapour, or as a solution, of strength 
of from 1 to 2 per cent, in distilled water, the results attained are 
most remarkable. All structures, such as cilia, cirrhi, and 
flagella, the internal endoblast, and in Euglena and its allies, the 
colours also are preserved, the animalcule, excepting for the 
absence of motion, being scarcely distinguishable from the living 
organisms. The author has found the most effectual and simple 
way of applying the osmic acid to be that of placing a drop on 
the cover before laying it on the slide containing the Infusoria. 
A saturated solution of potassic iodide in distilled water, satu- 
rated with iodine, and diluted to a brown sherry colour, has been 
found by the author to aCt in a manner almost identical with 
that of osmic acid, and in some instances even more efficiently, 
and possesses the additional advantage of yielding no deleterious 
exhalations, which have to be carefully guarded against in the 
use of osmic acid. 
The fourth chapter is devoted to a very exhaustive account of 
the vexed subject of spontaneous generation. No justice can be 
done in a mere abstract; ; full details are given of the elaborate 
experiments of Tyndall and Messrs. Dallingerand Drysdale, and 
the apparatus employed described and figured. As an instance 
of the almost universal distribution of infusorial germs, Mr, 
Kent’s account of the examination of some grass may be cited : 
“ On Saturday, October 10th, 1879, a day of intense fog, the 
author gathered grass, saturated with dew, from the Regent’s 
Park Gardens, the Regent’s Park, and the lawn of the Zoological 
Gardens, and submitted it to microscopical examination, without 
the addition of any supplementary liquid medium. In every 
drop of water examined, squeezed from the grass, or obtained by 
its simple application to the glass slide, animalculae, in their 
most aCtive condition, were found to be literally swarming, the 
material derived from each of the several named localities 
yielding, notwithstanding their close proximity, a conspicuous 
diversity of types [here follows a list of several species of Infu- 
soria, also two rotifers, and various diatoms, &c.], the collection 
as a whole being undistinguishable from the ordinary micro- 
scopic fauna of a roadside pond.” 
The data elicited through the observatious just recorded carry 
with them an important and far-reaching significance. In addi- 
tion to the conclusive proof herewith afforded of the primary 
origin of germs in hay, Infusoria and other minute forms of 
aquatic life were thereby demonstrated to possess an area of 
aCtive vital distribution hitherto undreamt of. Water, in its 
stable and concrete form, is no longer, as hitherto presumed, a 
requisite concomitant of such vital energy. The smooth-shaven 
lawn, park-land, and meadow, are each and all one vast teeming 
city peopled by its myriads of tiny inhabitants, heedlessly 
crushed under foot in our daily walks abroad. Securely housed 
in their spore-membranes or encystments, these microscopic 
