POST-MORTEM EXAMINATION OF ANIMALS 241 



though it not rarely occurs that bacteria are present in 

 such small numbers in the tissues that their presence may 

 be overlooked microscopically, and still they appear in the 

 cultures. 



If the autopsy has been performed in the proper way, 

 with the precautions given, and sufficiently soon after death, 

 the results of the bacteriological examination should be 

 either negative or the organisms which are isolated should 

 be in pure cultures. This is particluarly the case with cul- 

 tures made from the internal viscera. 



Both the cover-slips and cultures made from the point 

 of inoculation are apt to contain a variety of organisms. 



If the organism obtained in pure culture from the internal 

 viscera, or those predominating at the point of inoculation 

 of the animal, have caused its death, then subsequent 

 inoculation of pure cultures of this organism into the tissues 

 of a second animal should produce similar results. 



When the autopsy is quite finished the remains of the 

 animal should be burned; all instruments subjected to 

 either sterilization by steam or boiling for fifteen minutes 

 in a 1 to 2 per cent, soda solution; and the board upon which 

 the animal was tacked, as well as the tacks, towels, dishes, 

 and all other implements used at the autopsy, be sterilized 

 by steam. All cultures, cover-slips, and, indeed, all articles 

 likely to have infectious material upon them, must be 

 sterilized as soon as they are of no further service. 



What has been said with regard to the study of dead 

 tissues obtained at autopsy applies equally well to the 

 bacteriological study of tissues and exudates obtained during 

 life. In the latter case, however, certain precautions are 

 always to be observed. In the first place, it is desirable to 

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