282 MANUAL OF BACTERIOLOGY. 



not characteristic and injection into animals is without result, 

 it may be difficult to decide whether or not the organisms are 

 diphtheria bacilli. Consequently another view with regard to 

 pseudodiphtheria bacilli has arisen. While recognizing that 

 virulent diphtheria bacilU occur, it is also claimed that a dis- 

 tinct pseudodiphtheria bacillus exists, different from the diph- 

 theria bacillus, though resembling it. It is shorter, stains more 

 evenly, shows no polar granules by Neisser's method of staining, 

 does not produce acid in dextrose-bouillon, and is not patho- 

 genic to animals. It is found occasionally in the nose and 

 throat and has no connection with diphtheria, according to 

 this view.* But there are some who hold that there is no 

 pseudodiphtheria bacillus, and that the organism so called is 

 merely a more or less modified form of the diphtheria bacillus. 

 The diphtheria bacillus is pathogenic to animals. When 

 it is injected into them it produces a toxemia. In the- guinea- 

 pig, which is especially susceptible, local inflammation results, 

 and death occurs usually in two or three days. The bacilli 

 are found to be confined to the vicinity of the wound, and not 

 usually to be disseminated throughout the whole body. The 

 death of the animal, therefore, is due to the poisons elaborated 

 by the diphtheria bacilli — either poisons introduced at the 

 original injection, or substances produced by the bacilli which 

 may have multiplied in the animal's body. The internal vis- 

 cera, especially the liver, often exhibit small areas consisting 

 of necrotic cells; a transudation of serum takes place in the 

 great serous cavities, and the lymph-nodes are swollen. A 

 genuine diphtheritic membrane may be produced on the trachea 

 of a young kitten by rubbing into it a part of a culture of the 

 diphtheria bacillus. 



* The different sides of this question will be found fully discussed by the 

 following: Wesbrook, Wilson and McDaniel. Transactions of the Association 

 American Physicians. 1900. Gorham. Journal Medical Research. Vol. VI. 

 1900. A. Williams. Ibid. Vol. VIII. 1902. Denny. Ibid. Vol. IX. 1903. 

 Alice Hamilton. Journal of Infectious Diseases. Vol. I., No. 4. 1904. 

 Graham Smith. Journal of Hygiene. Vol. IV. 1904. 



