95 



gained in previous cultivations, it was not thought likely it 

 would give any information. But „cold in the head" and „sore 

 throat' during the last 3 months before the examination, were 

 inquired after. No relation could be detected as the following 

 figures show: 



This naturally is no more convincing as a proof that ca- 

 tarrhal affections do not favour the spread of Pfeiffer's bacil- 

 lus than the slight connection between past influenza and the 

 finding of the same microbe proves that influenza is of trifling 

 importance in its distribution. 



The chief result of the investigations concerning persons 

 not suffering from influenza is therefore, shortly expressed, 

 that Pfeiffer's bacillus in Denmark was very widely distributed 

 in such people, in the years in which the investigations took 

 place; that the distribution at any rate in healthy persons was 

 considerably greater in connection with each influenza epidemic 

 and afterwards decreased greatly in a few months (whether 

 an increase of distribution in patients with whooping-cough, 

 measles etc. follows influenza is not clear from my work); 

 that Pfeiffer's bacillus became widely disseminated among per- 

 sons who had not had influenza, and that the degree to which 

 this took place was largely influenced by the conditions under 

 which the individuals lived. 



My experiences of the occurrence of Pfeiffer's bacillus do 

 not alter the views put forward in the introductory chapters 

 (pp. 58—64). 



