28 



DAVID J. DAVIS 



TABLE 2. 

 OCCURRENCE OF INFLUENZA-LIKE BACILLI IN VARIOUS DISEASES AND IN NORMAL THROATS 



occur which will develop upon these media. In no instance did a 

 continuous growth occur when proper precautions were taken to use 

 fluids free from hemoglobin. Their cultural characteristics were 

 identical, and morphologically there were no constant differences 

 between them. In every group strains were found with a tendency 

 to marked thread formation, and there was also considerable varia- 

 tion in the size of the various strains, but nothing was observed that 

 would characterize any particular group. Animal experiments 

 showed that the bacilli from the different groups possessed about the 

 same pathogenic power as those isolated from whooping-cough cases. 

 Even those isolated from normal throats manifested the same low 

 degree of virulence as the other strains. A large quantity of the 

 bacilli is necessary to produce death, and the symptoms are not those 

 of a toxemia but of a general invasion, with numerous bacilli in the 

 blood. 



Literature. In the literature there are numerous references to 

 the occurrence of hemophilous bacilli in many infectious diseases 

 and diseases of the respiratory tract. They have usually been referred 

 to as influenza bacilli (Pfeiffer's bacillus), occasionally as pseudo- 

 influenza organisms, and for the most part have been looked 

 upon as secondary invaders, except in influenza, in which the 

 hemophilous bacilli have pretty generally come to be considered 

 as the specific organism. Pfeiffer, in 1893, in his classical work 

 on influenza, was the first to announce this, and since then an 

 enormous mass of literature has accumulated, most of which tends 

 to substantiate the idea that his bacillus is the specific cause of this 

 disease. If the evidence is carefully examined, however, it is found 



