174 LABORATORY METHODS OP 



of growth, both on and in the substance, presence or 

 absence of liquefaction, color, presence or absence of 

 gas formation, odor and relation to reaction of media, 

 streak culture, shake culture, plate culture and the 

 condition of the colonies. Note the reaction on agar 

 in the same way, also bouillon and special media. 

 Note reaction on animals when inoculated. 



Inoculating Animals. The animal is either a rat, 

 mouse, guinea-pig, or rabbit. Method : Take the ani- 

 mal, and sterilize the part selected for the operation, 

 and inoculate the same and watch results. If the ani- 

 mal dies in twenty-eight days, the germ is pathogenic. 

 But it usually dies in less time. The best location for 

 the inoculation is in the dorsal veins of the ear or the 

 root of the tail. 



Autopsies on Dead Animals. Method : Take a 

 strong cord, a trough and the dead animal ; tie the ani- 

 mal in the trough, soak the animal in carbolic acid 

 solution to prevent the dry hairs from flying in the 

 room during the autopsy, hence contaminating the air 

 of the room; now open the body and examine. The 

 animal should be burned after the operation. 



INOCULATION AND INCUBATION. 



To inoculate a tube of medium, take a culture and 

 place it between the thumb and index-finger; take a 

 tube of the medium that you are going to inoculate 



