310 PUBLIC HEALTH BACTERIOLOGY 



Larger, and more variation in size of individuals ; grows 

 best at room temperature ; non-pathogenic. 



3- B. Subtilis. The common bacillus of hay infusion, 

 and found as a saprophyte in old wounds and infected 

 sinuses ; gives a heavy tenacious pellicle in broth ; spores 

 germinate equatorially ; gelatin and casein are liquefied 

 more rapidly than by B. anthracis ; is actively motile in 

 young cultures ; non-pathogenic. Pathogenicity for man 

 is now alleged, it having been isolated from a case of 

 panophthalmitis in pure culture. 



4. B. Mycoides (earth bacillus). Is obtained from the 

 surface of the earth of cultivated fields or gardens. Grows 

 best at 18 C., and on gelatin shows a mould-like growth. 

 About the size of B. anthracis, which it resembles greatly. 

 Grows in threads ; motile ; non-pathogenic. 



5- B. Megatherium. 10 micra x 2-5 micra. First 

 found on boiled cabbage leaves. 



6. B. Vulgatus (potato bacillus). Grows rapidly on 

 potatoes, showing marked wrinkling. Small thick rods 

 with rounded ends, in pairs or fours. 



SPORE-BEARING ANAEROBIC BACILLI. 



Methods of Anaerobic Culture. 



1. Liquid media : Boil vigorously for 15 minutes, to 

 drive out dissolved oxygen ; cool, and put layer of sterile 

 oil on surface. (Pasteur.) 



2. Piece of sterile mica on surface of agar or gelatin 

 plates. (Koch.) 



3. Deep inoculation in solid media, recently boiled for 

 15 minutes and cooled rapidly in ice, to prevent absorp- 

 tion of oxygen. It is advantageous to have 1 per cent 

 of glucose in medium. The tubes are inoculated by deep 

 stabs, and the top of the medium is covered with a thin 

 layer of agar, gelatin, or oil. and the tube capped with 

 rubber or sealed with sealing-wax. (Liborius.) 



4. The solid medium may be inoculated before it 

 solidifies, a " shake culture " as in the original method 

 of Liborius. The colonies which develop are fished out 

 after breaking the tube. 



5. Tube fitted with two-holed cork and two tubes. 



