23 



Only exceptionally Pfeiffer's bacillus is absent in the early 

 stage of the disease and does not appear until later. 



12. Several observers demonstrated Pfeiffer's bacillus with 

 considerable frequency in healthy persons during the pan- 

 demic, but others hardly ever found it in such people. 



This may perhaps be explained by assuming that the ba- 

 cillus at first only developes in influenza patients and it takes 

 some time before it can spread from these to healthy indivi- 

 duals to any great extent. 



13. In certain cases during the pandemic it has been pos- 

 sible to demonstrate a constant relation between the 

 distribution of influenza and the occurrence of 

 Pfeiffer's bacillus not only in patients with influenza symptoms 

 but also in normal people and in patients with other 

 diseases (cf. 5). 



It will be appropriate here to give an account of the views 

 which have been formed in estimating the value of statements 

 about the finding of Pfeiffer's bacillus although part of the 

 basis of them can only be given later in connection with my 

 own investigations. 



Reports of negative findings must be accepted with great 

 reservation when there is inadequate information about the tech- 

 nique employed or whether the author in question has had 

 experience in the detection of Pfeiffer's bacillus. 



Reports of positive findings can as a rule be accepted 

 without further questioning when the bacillus is demonstrated 

 in culture, but microscopic examination alone is insufficient. 



It must however be remarked that Bruschettini (1—4) has in- 

 troduced some confusion by calling some microbes Pfeiffer's ba- 

 cillus which must be considered to be quite different (see Pfeiffer 

 & Beck (2) and Onorato), and several authors have built upon 

 his work without caution: Tizzoni (1), who however subsequently 

 (2) distinguishes between Pfeiffer's bacillus and Bruschettini's ba- 

 cillus, Bombicci, and Ghedini. 



Apart from this not only must the organisms which the 

 authors themselves take to be Pfeiffer's bacilli, be assumed to 

 be such but also Pfeiffer's „Pseudo-influenza bacillus", 

 Ei.massian's and Luzzato's bacilli, L. MOlusr's trachoma ba- 



