222 METHODS OF CULTIVATION 



AEROBIC. 



The Preparation of Tube Cultivations. 



The preparation of a tube cultivation consists in: 



(a) Inoculating a tube of sterile nutrient medium 

 with a portion of the material to be examined. 



(b) Incubating the inoculated tube at a suitable 

 temperature. 



The details of the first of these processes must be 

 varied somewhat according to whether the tubes of 

 nutrient media are inoculated or "planted" from 



1. Pre-existing cultivations. 



2. Morbid material previously collected (vide page 



373)- 



3 . Fluids, tissues, etc. , or from the animal body direct. 

 The method of preparing tube cultivations from 



pre-existing cultivations is as follows : 



1. Fluid Media (e. g., Nutrient Bouillon). 



i . Flame the cotton-wool plug of the tube containing 



FIG. 117. Inoculating tubes, seen from the front. 



the cultivation arid also that of the tube of sterile 

 bouillon. 



2. Hold the two tubes, side by side, between the 

 left thumb and the first and third fingers, allowing the 

 sealed ends to rest on the dorsum of the hand, and 

 separating the mouths of the tubes (which are pointed 

 to the right) by the tip of the second finger. Keep 



