91 



All the Pfeiffer's bacilli found were typical except 27 C, which 

 was atypical (yellow colour). After the previous experience 

 we might have expected a marked increase in the distribu- 

 tion of Pfeiffer's bacillus among the personel and residents of 

 the Serum Institute. That this has not proved to be the case 

 may perhaps be explained by the fact that the majority of the 

 persons examined live under good hygienic conditions as re- 

 gards dwellings etc. 



The constant and abundant occurrence of Pfeiffer's bacil- 

 lus in the soldiers examined on 14. I. 1919 cannot be directly 

 explained as the residue of influenza. The influenza infection 

 that 17 of them stated they had passed through, took place 

 about three months previously, and from my own experience 

 of influenza patients as well as that of others, it appears that 

 Pfeiffer's bacillus often vanishes after -the course of a few 

 days and probably in the vast majority of cases it will have 

 disappeared at the end of 3 months, if unusual conditions 

 do not come into play. What it is that causes Pfeiffer's ba- 

 cillus — just as Meningococcus — particularly to spread among, 

 and persist in, soldiers I am unable to explain. In view of 

 the fact that it is usually inclined to disappear spontaneously 

 in health}* persons, close association and the consequent easy 

 transmission of the microbe from one person to another 

 is not sufficient explanation. 



The relatively great distribution among soldiers is also 

 illustrated in a marked degree by the comparison already set 



