ANIMAL INOCULATION. 75 



will be found to adhere to it. This is called a Klatsch or 

 adhesion preparation. The preparation is dried, fixed, and 

 stained like any ordinary microscopic specimen, as will be 

 described later. 



Animal inoculation : Pure cultures may also be obtained 

 by animal inoculation. The suspected material is mixed with 

 a small quantity of sterile water and injected into the abdomi- 

 nal cavity, subcutaneous tissue, or ear vein of a mouse or 

 guinea-pig. This method is restricted almost entirely to 

 obtaining pure cultures of the tubercle or anthrax bacillus. 



All these various cultures can be preserved for museum 

 specimens by fixing them in formalin, which is applied in 

 the form of a spray or dilute solution; or the tubes are placed 

 in a tightly closed jar containing a little dilute formalin solu- 

 tion. After ten days they are removed and the ends of the 

 tubes are sealed in a flame ; or are stoppered with a cork or 

 wooden plug and dipped in paraffin. Cultures at different 

 stages of development and in all kinds of media may be thus 

 preserved and used for class-room instruction. They make a 

 very attractive and instructive museum exhibit. 



