85 



a similar nature, but in addition, a long series of newly- 

 enrolled soldiers has been examined, 1 — 2 days after 

 their arrival, — in the last investigation however, 3 days after. 

 They were persons who had journeyed directly from their 

 usual places of abode in very different parts of the country 

 and can therefore be regarded as „r a n d o m samples" of the 

 young healthy manhood of the whole country. Consequently, 

 from the investigations of a not too small number of such 

 persons carried out at various times, it will be possible to 

 get . a fairly reliable measure of the occurrence of Pfeif fer*s 

 bacillus among young healthy men in the whole country and 

 subsequently the variations in its distribution among them 1 . 

 Such variations must in all probability, be an indication of 

 similar variations in the population as a whole. 



Although the analysis of the mutual differences between 

 strains of Pfeiffer's bacillus will not be dealt with till later, it 

 will be convenient, in connection with the purely numerical 

 estimation of the findings in healthy people, to pay some at- 

 tention to the distinction between „typical" and „aty pi- 

 ca 1" Pfeiffer's bacilli. Regarding the significance of the ex- 

 pressions it need only be remarked here that practically only 

 typical Pfeiffer's bacilli are met with in influenza, while the 

 atypical are especially found in healthy persons. No sharp 

 boundary however can be drawn between the two groups. 



a. Newly-enrolled soldiers. 

 The results of these inoculations are given in tabular form 

 as well as graphically. 



1208 



The first column gives the date of examination, the 2nd. 

 column the number of soldiers investigated. Then follows the 



