OXYGEN RESPIRATION 



27 



Erlenmeyer flasks as follows (Fig. i). Through the tube c 

 a certain quantity of nutrient solution inoculated with fungus 

 spores would be run in until a height of only 1-1.5 cm. was 

 left between the surface of the solution {e-e) and the bottom 

 of the flask. The fungus mat then developed at the surface of 

 the liquid. By opening the pinch cock d the nutrient solution 

 can be let out whenever necessary and be replaced by another 

 nutrient solution after rinsing off the lower surface of the fungus 

 mat. When the liquid runs out no change occurs in the position 

 of the compact fungus mat. Its center merely sags somewhat. 

 For the determination of the carbon dioxide formed by large 

 amounts of the expressed juice of Psalliota 

 campesiris [= Agaricus campestris], Kostychev 

 made use of large, and like-wise inverted, cylin- 

 drical-conical flasks (Fig. 2). For work with 





Fig. I. — Flask for experi- 

 mepts with molds. 



Fig. 2. — Flask for study- 

 ing COs-formation by plant 

 juices. 



Fig. 3. — Chudia- 

 kow's vessel. 



small volumes of Hquids, the use of Chudiakow's apparatus 

 (Fig. 3) is to be recommended. The arrow indicates the direc- 

 tion of the current of gas. 



For his studies of the respiration of the lower plants, Palladin^ 

 set up roll cultures on gelatine. A narrow-mouthed glass bot- 

 tle was very well suited to this purpose, the mouth being fitted 

 with a two-hole rubber stopper and an entry and an exit tube 

 inserted in the holes. Palladin used large cylinders of 350-650 

 cc. capacity or test tubes of about 600 cc. capacity. The walls 

 of the sterilized cylinder were coated with a thin layer of hot, 



1 Palladin, W. Zentralbl. f. Bakt., Parasitenk. u. Infektions krankh. (II) ii: 146. 

 1903. 



