744 SUMMARY OF CURRENT RESEARCHES RELATING TO 
into a hot solution of soda-soap, and then dried. A further cleaning 
with absolute alcohol and whiting is also advisable. Ordinary petroleum 
may also be used with advantage for removing rust. Paraffin oil is 
recommended as the best means of protecting steel instruments from 
rust. To avoid using excess of oil, the best method of procedure is to 
take a solution of 1 part paraffin oil in 200 parts benzine, to immerse 
the instruments in this solution, and afterwards place them on a plate 
in a dry room where the benzine may evaporate. 
B. Technique.* 
Cl) Collecting Objects, including Culture Processes. 
Aseptic Protozoa Cultures.! — Dr. C. 0. Miller says that in the 
preparation of Protozoa cultures it is necessary to be extremely careful 
to prevent contamination of the media, and greater precautions are 
required for liquid than for solid media. For direct examination of the 
appearances occurring in the cultures he used sterilized moist chambers, 
hanging drops, Petri’s capsules and ordinary tumblers. The most trust- 
worthy cultures were made in Erlenmeyer’s flasks holding 100-200 ccm. 
Discontinuous sterilization was usually employed, the media being steam 
sterilized for 15 minutes on three successive days. For some experi- 
ments an autoclave was used for 15 minutes at a pressure of two atmo- 
spheres. Inoculations or transplantations may be made with a platinum 
loop, but it is better to use a pipette. A couple of dozen pipettes 
(from 18-20 cm. long) may be sterilized together. The author adds 
many cautions and precautions too minute to give in full, but these may 
be easily apprehended. The infusions used were neutralized bouillon 
2-4 parts to 100 of water; 1/2 per cent, glycerin in which is placed a 
little bit of tendon 1 mm. square ; linseed decoction diluted down to the 
colour of white wine; dilute hay infusion with 1/2 per cent, grape sugar 
or 1/5 per cent. milk. These dilute solutions give better results than 
thicker ones. After filtration, 1-1J ccm. were placed in the glass 
vessels. One of the greatest difficulties in these cultivations is the 
presence of fungi, though most of these are got rid of at a temperature 
of 37*0°, which is unsuitable to them and favourable to Amoebae, 
Plasmodia, and many other Protozoa. 
Apparatus for Pure Cultivation of Algae.! — Herr P. Kossowitsch 
adopted the following arrangement for the pure cultivation of Algae. On 
the bottom of an Erlenmeyer’s flask (fig. 90) having a diameter of 
15 * 5 ccm. is placed a thin layer of sand. The neck of the flask is plugged 
with a triply perforated caoutchouc stopper. Through one of the holes 
passes the glass tube d , which reaches nearly to the bottom of the flask. 
* 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.; 
(G) Miscellaneous. 
f Centralbl. f. Bakteriol. u. Parasitenk., xvi. (1894) pp. 273-80. 
J Botanische Zeitung, Jahrg. 52 (1894) pp. 101-3 (2 figs.). 
