484 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Fig, 94. 
vessel, the neck of which is plugged with a rubber stopper with two 
perforations, through which pass two U-shaped tubes. To one of 
these is fitted a glass nozzle through 
the intermediary of a piece of rubber 
tubing. Into the rubber tube is pressed 
a solid glass ball with a diameter larger 
than that of the lumen of the rubber 
tube. The vessel having been filled, 
the flow is secured by merely pressing 
the tube immediately above the head D. 
In this way a steady stream or single 
drops are made to issue from the 
nozzle (fig. 94). 
The Microscope and its Applica- 
tion.* — The concluding portion of 
Prof. L. Dippel’s work on the Micro- 
scope and its Application has recently 
appeared. It contains the third and 
fourth sections which deal with the 
structure of the stem, the root and 
leaves, and also with the development of the various parts of plants. 
It is copiously illustrated with woodcuts. 
B. Technique. f 
! (1) Collecting- Objects, including- Culture Processes. 
Method for Making Anaerobic Roll-Cultures with Gelatin or 
A gar 4 — The following simple method for making anaerobic roll- 
cultures is given by Herr G. Marpmann. Two test-tubes are required, 
one of which can be pushed just inside the other. The larger is then 
1/4 filled with the medium and sterilised. The medium is inoculated, 
and then stirred up with a glass rod for 5-10 minutes. The smaller 
tube is now jammed inside the larger, its surface having been previously 
sterilised in the flame. The layer of inoculated medium is set by 
plunging the tubes into cold water. The ends of both are sealed with 
paraffin or covered with a rubber cap. The colonies are easily counted. 
Inoculations can be made from any particular colony by merely with- 
drawing the inner tube, or by cutting through the glass. 
Cultivation Media suitable for Tropical Climates.§ — M. A. Morel, 
writing from Java, w r here the mean temperature is over 25° 0., states 
that he has been in the habit of using for some time past a culture 
medium which remains firm at the hottest season of the year. It is 
composed of 12J parts white gelatin, 0*25 parts agar, and 90 parts 
* Braunschweig, F. Vieweg u. Sohn, 1898, pp. 445-644, with Index, Contents, 
and 132 woodcuts. 
t This subdivision contains (1) Collecting Objects, including Culture Pro- 
cesses; (2) Preparing Objects ; (3) Cutting, including Imbedding and Microtomes ; 
(4) Staining and Injecting ; (5) Mounting, including slides, preservative fluids, &c. ; 
(6) Miscellaneous. 
% Zeitschr. f. angew. Mikr., iv. (1898) pp. 37-8. 
§ Tom. cit., pp. 4-6. 
