Exclusion of Atmospheric Oxygen 267 



with a rubber tube, E, at the end, and one interruption 

 connected by a rubber tube, C. The device will be made 

 clear at once by a glance at the accompanying illustration. 

 The method of employment is very simple. An ordinary 

 tube of bouillon or other fluid culture media receives the 

 pipet, the whole being sterilized, the cotton plug in place. 

 The bouillon being inoculated with the culture or secretion 

 to be studied is drawn up in the bulb of the pipet, A, by 

 suction, until it passes the rubber interruption, C. By 

 forcing the upper end of the pipet downward in the test-tube, 

 a kink is given each rubber tube and the fluid contained in 

 the bulbous part of the pipet becomes hermetically sealed. 



In all cases where the presence of suspected micro- 

 organisms is to be demonstrated, it is necessary to make 

 both aerobic and anaerobic cultures. For routine work of 

 this kind, this method of Wright is probably the most con- 

 venient yet suggested. 



