PATHOGENIC PROPERTIES. 335 



fluid cultures into the testicles of guinea-pigs) diph- 

 theria bacilli can be caused to appear in the omentum, 

 but this is purely an artificial manifestation of the dis- 

 ease 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 either a solid or fluid 

 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 oedema, 

 with more or less hypersemia and ecchymosis at the 

 site of inoculation; swollen and reddened lymphatic 

 glands; increased serous fluid in the peritoneum, pleura, 

 and " pericardium ; enlarged and hemorrhagic adrenal 

 bodies; occasionally slightly swollen spleen; and some- 

 times fatty degeneration in the liver, kidney, and myo- 

 cardium. In guinea-pigs, especially, the liver often 

 shows numerous macroscopic dots and lines on the sur- 

 face and penetrating the substance of the organ. They 

 vary in size from a pin-point to a pin-head, and may be 

 even larger. They are white and do not project above 

 the surface of the capsule. 



The bacilli are always to be found at the seat of inoc- 

 ulation, most abundant in the grayish-white, fibrino- 

 purulent exudate. They become fewer at a distance 

 from this, so that the more remote parts of the oedema- 

 tous tissues do not contain them. They are found not 

 only free, but contained in large number in leucocytes, 

 some of which have fragmented nuclei, or have lost 

 their nuclei. The bacilli within leucocytes, as well as 

 some outside, frequently stain very faintly and irregu- 

 larly, and may appear disintegrated and dead. 



