72 ESSENTIALS OF BACTERIOLOGY 



means of a long platinum rod with small loop, the movement 

 being a rotary vertical one, and the rod going to the bottom 

 of the tube. 



The gelatin is next quickly solidified under ice; very little 

 air is present. The anaerobic germs will grow from the 

 bottom upward, and any aerobins present will develop first 

 on top, this method being one of isolation. 



From the anaerobic germ grown in the lower part, a stab- 

 culture is made into another tube containing three-quarters 



Fig. 40. Liborius's method. 



Fig. 41. Hesse's method of making 

 anaerobic cultures (McFarland). 



gelatin, the material being obtained by breaking test-tube with 

 the culture. (See Fig. 40.) 



Hesse's Method. A stab-culture having been made with 

 anaerobic germs, gelatin in a semisolid condition is poured 

 into the tube until it is full, thus displacing the air (Fig. 41). 



Esmarch's Method. Having inoculated a tube, the gela- 

 tin is rolled out on the walls of the tube, a " roll culture," 

 and the rest of the interior is filled with gelatin, the tube 



