ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 105 



at 100°, 25 c.cm. The medium is then poured into the constricted tubes,, 

 covered with oil, and then the tubes are incubated for 48 hours. 



In order to study isolated colonies, the author uses a flat tube 

 with a long drawn out extremity (fig. 2D), and holding about 8 c.cm.. 

 The agar or gelatin to be used is liquefied in test-tubes, inoculated, and 

 diluted. The point of the long arm is then broken off at h, and then 

 inserted into the tube containing the medium. By sucking at a the 

 flat tube is filled as far as the neck. The neck and point are then 

 melted off at b and/, and the closed plate placed in the incubator. As 

 the tube is flat the colonies can be examined under the Microscope, and 

 also easily photographed. By means of the media and this apparatus, 

 the author has very successfully cultivated numerous anaerobic bacteria- 

 Cultivating' the Influenza Bacillus.* — E. Czaplewski makes a blood- 

 agar culture medium with pigeon's blood. Some feathers are removed 

 with scissors from the bird's breast, and the surface thoroughly cleansed 

 with cotton-wool soaked with alcohol. A slight incision is then made 

 with a lancet, and the blood withdrawn by means of a pipette. The 

 blood is then squirted into a flask, on the bottom of which is a layer of 

 liquid agar (about 10 c.cm.). The ingredients are then mixed by careful 

 shaking. The flask should be kept in a water-bath to prevent the agar 

 setting. More agar is poured in until the correct tone of colour is 

 obtained. The mixture is then passed into test-tubes or Petri dishes, 

 and slants or plates made. With the usual precautions, such as are now 

 employed in bacteriological laboratories, contaminations of the blood- 

 agar are quite rare. 



Meyer, E. — Einige neue Apparate zum Schopfen von Wasser zu bacteriologischen. 

 Zwecken. (New apparatus for obtaining water tor bacteriological purposes.) 



Centralbl. Bald., l ta Abt. Orig., XXXII. (1902) pp. 845-8 (4 figs.). 



(3) Cutting, including Imbedding and Microtomes. 



Simple Method of Making Thin Paraffin Sections.f — W. Kolmer 

 and H. Wolff describe a new procedure for making paraffin sections 

 without the employment of fixatives. The chief agent is carbonic 

 acid. To the cylinder containing the liquid gas is attached a tube 

 20 cm. long. Over the tube is placed a bag made of two layers of 

 velvet. The bag is about the size of a child's head, and is fastened to 

 the tube with strings and a clamp. The tap is opened for a moment. 

 The bag becomes filled with solid C0 2 , which is transferred to a pan 

 and stamped down with a pestle. After repeating the process several 

 times, a cake of solid carbonic acid is obtained which will retain a tem- 

 perature of about — 80° C. for 10-12 hours. 



The cake is then put in an exsiccator, on the bottom of which is 

 placed a small copper tube containing paraffin (melting-point 32°). On 

 the layer of paraffin is placed the piece of fresh tissue (50 c.cm. in bulk). 

 The piece freezes instantly. A dish of pentoxide of phosphorus is also 

 placed in the exsiccator. The air is then removed by means of a water 

 or mercury pump. In about 100 hours the piece of tissue is freed from 

 its water. The exsiccator is then put in a thermostat to thaw the piece 



* Centralbl. Bakt., l t0 Abt. Orig., xxxii. (1902) pp. 667-70. 

 t Zeitschr. f. wiss. Mikr., xix. (1902) pp. 148-50. 



