ANTHRAX. 287 



attack of influenza, but this must, however, be considered 

 as only temporary. 



Pseudo-influenza-bacilli. In a number of broncho- 

 pneumonic foci in patients not suffering from influenza (but 

 from diphtheria) Pfeiffer found bacilli that in form and stain- 

 ing properties resembled influenza-bacilli, and that, like 

 these, developed exclusively upon blood-agar. Similar 

 bacilli have since been isolated by various observers from 

 cases of otitis media and of influenza. Pfeiffer believes these 

 organisms to be related to influenza-bacilli, and he desig- 

 nates them pseudo-influenza-bacilli. They are to be dis- 

 tinguished from true influenza-bacilli by culture, in which, 

 after the lapse of twenty-four hours, they appear consider- 

 ably larger in all dimensions, and they exhibit a marked 

 tendency to the formation of long pseudo-filaments. In 

 similar cultures of the true bacillus the latter are wanting 

 entirely or appear but exceptionally. 



Bacteriologic Diagnosis of Influenza. The bacterio r 

 logic diagnosis is made from examination of the sputum 

 derived from the deepest possible portions of the air- 

 passages, and thus preferably from examination of the 

 bronchial sputum. Microscopic examination alone is usu- 

 ally insufficient, but, as a rule, cultivation of the bacillus is 

 necessary, the method for which has already been described 

 in detail (p. 283, Plate-procedure). Bacteriologic examina- 

 tion may acquire differential diagnostic significance. Thus, 

 Borchardt relates a case in which the diagnosis oscillated 

 for a long time between typhoid fever and influenza, until 

 bacteriologic examination decided in favor of the latter. 



ANTHRAX. 



Pollender, in Germany, in 1 849, and Rayer and Davaine, 

 in France, in 1850, were the first, independently of each 

 other, to detect bacilli in the blood of animals suffering 

 from anthrax. The growth of the anthrax-bacillus in 

 pure culture and the experimental development of the dis- 

 ease by means of the bacillus were successfully accom- 

 plished first by Koch in 1876. 



Morphology of the Anthrax-bacilli. Anthrax-bacilli 

 appear as transparent, homogeneous, nonmotile rods. They 

 are from i to 1.5 ju thick, and from 5 or 6 to IG/J. long, but they 



