Zoology and botany, microscopy, etc. 
641 
disseminated is inoculated on oblique agar which has been treated with 
blood, or the agar may be inoculated directly. In the first case 
colonies appear in 24 hours, in the latter in 12—15 hours, though these 
are often mixed with other bacteria. The author also cultivated on 
agar plates mixed with a few loopfuls of human or rabbit s blood. On 
such plates the small homogeneous structureless influenza colonies are 
easily distinguishable from other bacterial growths. 
Natural Injection.* — Dr. E. Ketterer has a note on Herr K. 
Zellner’s \ method of “ natural injection,” which is similar to one which 
he has himself used.J Portions of a body whose blood has been retained 
are cut into fragments about 3 cm. in diameter, placed in Muller’s fluid 
for at least 24 hours, washed for 2 hours in a current of water, gradually 
saturated with alcohol, cut in paraffin, stained for 24 hours in Biondi- 
Heidenhain’s mixture, washed and dehydrated as usual. Then it is 
seen that the red blood-corpuscles have a golden yellow colour, which 
beautifully marks the course of the blood-vessels. 
(5) Mounting 1 , including Slides, Preservative Fluids, &c. 
Method for Mounting Opaque Objects. — At the meeting of the 
Society in June last Mr. J. J. Harvey read the following note on his 
method of mounting opaque objects, which allows of the object being 
rotated when examined under the Microscope. 
“ One of the many objections to the present system of mounting 
opaque objects is that it is necessary to permanently hide one side of 
the specimen, and in the case of aberrant or rare forms this may greatly 
lessen the value and interest of the slide. The method here advocated 
allows of the revolution of the object under the Microscope, and permits 
of its examination with as much ease as a hand specimen. It is at the 
same time as permanent and as compact as the older system. Another 
important advantage is the differential lighting which this rotation 
brings into play, and which the inventor has found of special service 
in the study of the Foraminifera for which this method was originally 
designed. The slides used are the wooden slips recommended for this 
class of objects by Carpenter and others. The specimen is attached by 
means of a suitable medium to the end of a needle (fig. 79, B) which 
has been thrust through the centre of a plug of india-rubber cord C. 
* Journ. de l’Anat. et de la Physiol., xxx. (1894) p. 336. 
t Archiv f. Pathol. Anat. u. Physiol., cxxxv. p. 147. 
% Journ. de l’Anat. et de la Physiol., 1888, p. 324. 
