348 APPLICATION OF METHODS OF BACTERIOLOGY 



and is the organism most frequently concerned in the pro- 

 duction of acute, circumscribed, suppurative inflammations. 

 As it is almost ubiquitous, it is a source of continuous 

 annoyance to the surgeon. 



While it is the etiological factor in the production of most 

 of the suppurative processes in man, still it is with no little 

 difficulty that these conditions can be reproduced experi- 

 mentally in lower animals. Its subcutaneous introduction 

 into their tissues does not always result in abscess formation, 

 and when it does there is probably coincident interference 

 with the circulation and nutrition of these tissues which 

 renders them less able to resist its inroads. When intro- 

 duced into the great serous cavities of the lower animals 

 its presence is likewise not always accompanied by the 

 production of inflammation. If the abdominal cavity of 

 a dog, for example, be carefully opened so as to make as 

 slight a wound as possible, and no injury be done to the 

 intestines, large quantities of bouillon cultures or watery 

 suspensions of this organism may be, and repeatedly have 

 been introduced into the peritoneum without the slightest 

 injury to the animal. On the contrary, if some substance 

 which acts as a direct irritant to the intestines such, for 

 example, as a small bit of potato upon which the organisms 

 are growing be at the same time introduced, or the intes- 

 tines be mechanically injured, so that there is a disturbance 

 in their circulation, then the introduction of these organisms 

 is promptly followed by acute and fatal peritonitis. (Hal- 

 sted. 1 ) 



On the other hand, the results which follow their introduc- 

 tion into the circulation are practically constant. If one 



1 The Johns Hopkins Hospital Reports. Report in Surgery, No. 1, 

 1891, ii, No. 5, 301-303. 



