304 MEDICAL BACTERIOLOGY 



The method is as follows : 



( 1 ) Heat a scalpel and scorch a small surface of the organ from 

 which the cultures are to be made. 



(2) Heat the scalpel again and penetrate the capsule of the 

 organ with the point, and through the opening insert a stout ster- 

 ilized platinum loop, push it into the tissues, twist around, and 

 obtain enough material from the center of the organ to make the 

 culture. Cultures from blood are usually made from one of the 

 heart cavities, the surface being seared with a hot knife before 

 opening. 



As soon as the culture material is obtained, cover-glass speci- 

 mens are prepared from each organ and from existing exudates. 



Small pieces of each organ are also preserved for future exam- 

 ination. 



When the autopsy is finished the remainder of the animal should 

 be burned 1 and the instruments should be sterilized (see p. 300). 

 Wash the post-mortem board with sublimate solution. The cover- 

 glasses and other material likely to contain infectious matter must 

 also be sterilized when of no further use. 



Cultures are to be incubated at 38 C., growth examined micro- 

 scopically, and by means of sub-cultures. 



Use blank on p. 308 for preservation of data. Fig. 37 shows the 

 method of making a post-mortem and the location of the most im- 

 portant lymphatic glands. 



REFERENCES. The above is taken largely from Bowhill, 74 ; see 

 also A. 230 ; N. 260 ; and other texts. 



COMMON LABORATORY EXPERIMENTS. 



The following inoculations are those most frequently made : 



Streptococcus erysipelatos. Mice or rabbits, intravenous. 



M. pyogenes var. aureus. Rabbit, intravenous. 



Sarcina tetragena. Guinea pigs and white mice, subcutaneous. 



Bacterium anthracis. Guinea pigs or rabbits, subcutaneous. 



Bacterium cholerae. Rabbits and pigeons, subcutaneous. 



Bacterium pneumoniae. Rabbits and mice, subcutaneous. 



Bacterium pneumoniae. Rabbits and mice, subcutaneous with 

 sputum. 



Bacterium pneumonicum. Mice and young rats, intraperitoneal. 



Bacterium tuberculosis. Guinea pigs, rabbits and field mice, 

 subcutaneous or intraperitoneal. 



1 For small animals a muffle furnace does very well. 



