ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 663 



For those who have to rely upon the ordinary Microscope and for 

 any work with high powers, the living " foram " must be removed to a 

 cell or excavated slip. After the specimen has been located on the glass 

 side of the aquarium it must be detached with a needle or fine brush with 

 one hand, and as it falls down the side of the tank must be caught with a 

 pipette held in the other. Foraminifera are very sensitive to vibration 

 or shock, and draw in their pseudopodia rapidly, but in most instances 

 they will quickly recover when placed on the stage of the Microscope, and 

 again protrude them. The first sight of a fine Polystomella or Massilina, 

 with its pseudopodia fully extended, is indeed an experience never to be 

 forgotten. 



New Method of Preparing Culture Media.* — C. Gessard is of 

 opinion that the repeated sterilizations required in the preparation of 

 ordinary media, must cause alterations in the constituents, which are 

 undesirable for some purposes. He has, therefore, made use of a method 

 of preparing media without using heat. Three parts of blood, drawn 

 from a vein under aseptic conditions, are received into a vessel containing 

 1 part of a 20 p.c. salt solution. The strong saline inhibits the process of 

 clotting, but if the mixture be diluted with nine times its volume of water, 

 a clot is formed. Suitable quantities of the concentrated saline mixture 

 are introduced into test tubes, and diluted with sterile distilled water. The 

 tubes are sloped if desired. A clot soon forms, which constitutes the 

 culture medium. As all the manipulations have been conducted so as 

 to avoid contamination, no further sterilization is necessary. The 

 medium may be modified by the addition of sugars, glycerin, or other 

 materials. 



Isolation of Cholera Vibrios. f — Finding the stereotyped peptone- 

 water method unsatisfactory for separating the vibrio from Bacillus 

 pyocyaneus and certain other organisms, M. Crendiropoulo and A. Panayo- 

 tatou have discovered a medium upon which these extraneous organ- 

 isms are more effectively inhibited. A solution of peptone — Witte's 

 for preference — is made alkaline by the addition of soda, so that 

 its reaction is between 0*28 and 0*4 p.c, expressed in terms of 

 soda. When the medium is required for use, 2 parts of this solution 

 are added to 3 parts of neutral peptone agar. The mixture is poured 

 into Petri dishes, and allowed to set. It may then be spread with an 

 emulsion of the suspected material. 



The authors also made trial of Dieudonne's alkaline hasmo-agar, but 

 found that the latter did not always restrain B. pyocyaneus. Moreover, 

 the colour of this medium made it difficult, in some cases, to distinguish 

 the colonies of the two organisms. 



Mdllee, A. — Tiber den Einfluss des Gehalts der Gelatine an schwefliger Saure 

 auf ihre Verwendbarkeit in der bakteriologischen Technik. 



Arb. Kaiserl. Gesund., xxxiv. (1910) pp. 164-5. 



* C.R. Soc. Biol. Paris, lxviii. (1910) pp. 1049-50. 



t Centraibl. Bakt. lte Abt. Orig., lv. (1910) pp. 248-250. 



