520 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



B. Technique.* 

 (1) Collecting- Objects, including- Culture Processes. 



New Anaerobic Apparatus.! — 0. Lentz describes a simplified method 

 of cultivating anaerobes upon Petri dishes. This consists in an applica- 

 tion of the pyrogallic and potash method, and the materials are prepared 

 in the following way. Disks of blotting-paper, of a diameter of 8 ' 7 cm. 

 and thickness of 0*6 cm., are soaked first in a watery and next in an 

 alcoholic pyrogallol solution. Disks so prepared remain serviceable for 

 about a week. To facilitate the subsequent observation of colonies the 

 centre of the disk is cut out, leaving a ring of the "pyrogallic cushion" 

 with an internal diameter of -4-5 cm. Such a ring is placed upon a glass 

 plate of about 12 cm. square, and is then edged with a pencil of plasti- 

 cine. The plate, gelatin, agar, or the like, is then inoculated and placed 

 for the moment in the Petri cover. Then about 15 c.cm. of 1 p.c. 



Fig. 73. 



watery potash is poured over the pyrogallol pad and the plate is imme- 

 diately inverted over it (fig. 73). The plasticine is then worked so as 

 to make an efficient air-tight joint. The author tested the excellence 

 of the anaerobic conditions obtained by attempting to cultivate strict 

 aerobes, such as the Vibrio ckolerse, and by decolorising media stained 

 with methylen-blue. Both tests were most satisfactory. The author has 

 also devised a modification of this method applicable to tubes and flasks. 



Method of Obtaining Yeast-spores. } — A. Gorodkowa uses the 

 following medium : water 100, agar 1, pepton 1, broth 1, sodium chloride 

 • 5, glucose • 25. Slopes are made, and, after inoculating with yeast- 

 cells, are incubated at 28°G. Spores form in two or three days. 



* 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, etc. ; 

 (6) Miscellaneous. 



t Centralbl. Bakt., lte Abt. Orig., liii. (1910) pp. 358-65. 



X Bull. Jard. Imp. Bot. Petersbourg, through Zeitschr. wiss. Mikrosk., xxvi. 

 (1909) p. 583. 



