250 BACTERIOLOGY. 



of which have fragmented nuclei or have lost their nuclei. 

 The bacilli within the leucocytes as well as some outside 

 frequently stain very faintly and irregularly, and may 

 appear disintegrated and dead. 



In all cases culture-tubes inoculated with the blood, 

 spleen, liver, kidneys, supra-renal capsules, distant 

 lymphatic glands, and serous transudates yield nega- 

 tive growths. Negative results are also always obtained 

 when these organs are examined microscopically for the 

 bacilli. 



Microscopic examinations of the tissues about the seat 

 of inoculation, as well as of the liver, spleen, kidneys, 

 lymphatic glands, and elsewhere, show a condition of 

 extensive cell-death which is characterized by an extreme 

 degree of fragmentation of the nuclei of the cells of these 

 parts. These peculiar alterations, as Oertel has shown, 

 in their distribution are characteristic of human diph- 

 theria, and the demonstration of similar changes in 

 animals inoculated with this organism is no small 

 additional proof that diphtheria is caused by it. 



An affection may be produced by the inoculation of 

 certain animals in all respects identical with the disease 

 diphtheria as it exists in man. If one opens the trachea 

 of a kitten and rubs upon the mucous membrane a small 

 portion of a pure culture of this organism, the death of 

 the animal will ensue in from two to four days. At 

 autopsy the wound will be found covered with a gray- 

 ish, adherent, necrotic, distinctly diphtheritic layer. 

 Around the wound the subcutaneous tissues will be 

 oedematous. The lymphatic glands at the angle of the 

 jaws will be swollen and reddened. The mucous mem- 

 brane of the trachea at the point upon which the bacilli 

 were deposited will be covered with a tolerably firm, 



