220 



The Cultivation of Anaerobic Organisms 



culture medium with a U-shaped tube, to the other end of which 

 is attached a tube to contain the pyrogallic acid solution. The 

 apparatus will at once be understood by a glance at the cut. 

 The mode of employing it is as follows: "After inoculating the 

 culture-tube the plug is pushed in a little below the lips of the tube; 

 the ends of the U'tube and the test-tubes are coated externally with 

 vaselin, the rubber tubes are adjusted on the U tube and a connec- 

 tion made with the culture-tube so that the glass ends meet. One 

 or two grams of pyrogallic acid are put in 

 the empty test-tube, and packed down 

 with a little filter-paper over it; ten or 

 twenty cubic centimeters, respectively, of 

 a lo per cent, solution of sodium hydroxid 

 are then poured into the tube and the 

 second connection made before the acid 

 and alkali react to any extent." 



Wright has suggested that the cotton 

 stopper of the ordinary culture-tube have 

 its projecting part cut off and the plug 

 itself pushed down the tube for a short dis- 

 tance. Some alkaline p3Togallic acid solu- 

 tion is poured upon the cotton, to saturate 

 it, and the tube tightly corked. 



Zinsser* has recommended the follow- 

 ing method as satisfactory for use with 

 Petri dishes. The dishes selected should 

 be rather deeper than ordinary. They 

 are sterilized and inoculated in the 

 ordinary manner and then inverted. The 

 dish is cautiously raised, and some pyro- 

 gallic acid carefully poured into the lid 

 and the dish gently dropped into place 

 again. The alkaline solution is then 

 poured into the crevice between the edges 

 of the dish and the lid, and the remainder 

 of the space filled with melted albolene. 

 When these dishes are carefully stood 

 away, the alkaline pyrogallic acid absorbs 

 all of the contained oxygen and the 

 anaerobic cultures develop quite well. The growing colonies can 

 be examined as often as may be necessary through the bottom of 

 the dishes, which must, of course, always be kept in the inverted 

 position. 



4. Reduction of Oxygen. — Pasteur and, later, Roux have recom- 

 mended the cultivation of anaerobic bacteria in association with 

 aerobic bacteria by which the oxygen was to be absorbed. This 

 * "Journal of Experimental Medicine," 1906, viii, 542. 



Fig. 59. — Spirillum ru- 

 brum. Glucose agar slant 

 culture of five days. Abun- 

 dant production of pigment 

 on the surface. (The U tube 

 was soiled by the reducing 

 fluid during handling by the 

 photographer.) (Nichols 

 and Schmitter.) 



