THE BACTERIOLOGICAL LABORATORY 45 



which is then plugged with cotton-wool. The 

 fluid is sterilised by heating in the usual way ; 

 and is inoculated by nipping off the sealed end 

 of the lateral arm, and introducing the inoculating 

 needle through the orifice. The needle deposits 

 the material on the opposite side of the tube : it is 

 then withdrawn and the lateral orifice again sealed. 

 The fluid is then tilted so as to wash down the 

 inoculating matter. The inoculated tube is then 

 placed in an incubator. 



The remaining tubes, flasks, 

 and pipettes (see Fig. 17) are 

 ati used in the cultivation of 

 microbes. Some are used for 

 storage purposes ; while others 

 are used as culture tubes, 

 flasks, etc. A very good stor- 

 age flask has been recently 

 described by Dr. Sims Wood- 

 head. 1 This flask (Fig. 18) was 

 devised in order to do away FIG. is. 



.., ., , , ,11 WOODHEAD'S STORAGE FLASK. 



with the troublesome method 

 of filling test-tubes, etc., with a pipette. A large 

 flask (containing bouillon) is fitted with an india- 

 rubber stopper with two holes. ' Through these 

 pass two tubes, one with a thistle-head tube run- 

 ning to near the surface of the fluid, i.e. about 

 two-thirds of the distance down into the flask, 

 the other passing just through the stopper. To the 

 shorter tube is fitted a piece of india-rubber tubing 



1 Proceedings of Royal Physical Society of Edinburgh, vol. ix. 

 p. 537. 



