490 APPLICATION OF METHODS OF BACTERIOLOGY 



we shall have to deal, but the bacillus of diphtheria remains 

 localized at the point of inoculation, rarely disseminating 

 further than the nearest lymphatic glands. It develops at 

 the point in the tissues at which it is deposited, and during 

 its development gives rise to changes in the tissues which 

 result entirely from the absorption of poisons generated by 

 the bacteria in the course of their development. 



Occasionally diphtheria bacilli may be found in the 

 blood and internal organs of individuals dead of the disease; 

 but all that has been learned from careful study of the 

 secondary manifestations of diphtheria tends to the opinion 

 that they are in no way dependent upon the immediate 

 presence of bacteria, and that the occasional appearance 

 of diphtheria bacteria in the internal organs is in all prob- 

 ability accidental, and usually unimportant. 



By special methods of inoculation 1 (the injection of fluid 

 cultures into the testicles of guinea-pigs) diphtheria bacilli 

 can be cawed to appear in the omentum; but this is purely 

 an artificial manifestation of the disease, and one that is 

 probably never encountered in the natural course of events. 

 More rarely similar results follow upon subcutaneous 

 inoculation. 



If a very minute portion of a virulent pure culture of 

 this organism be introduced into the subcutaneous tissues 

 of a guinea-pig or kitten, death of the animal ensues in 

 from twenty-four hours to five days. The usual changes 

 are an extensive local edema, with more or less hyperemia 

 and ecchymoses at the site of inoculation; swollen and red- 

 dened lymphatic glands; increased serous fluid in the peri- 

 toneum, pleura, and pericardium; enlarged and hemorrhagic 



1 Abbott and Ghriskey, A Contribution to the Pathology of Experi- 

 mental Diphtheria, The Johns Hopkins Hospital Bulletin, No. 30, April, 

 1893. 



