454 HEMOGLOBINOPHILIC BACILLI 
typical cases. The incubation period is usually brief— from one to 
three days, as a rule. Pleurisy is a frequent complication, usually 
caused by a secondary infection with pneumococci or streptococci. 
Influenzal meningitis/ pharyngitis and laryngitis,- and conjunctivitis^ 
are not uncommon. Relapses are not infrequent. 
Unsuccessful attempts to induce typical influenza in man and 
experimental animals by direct implantation of freshly isolated strains 
of the Pfeift'er bacillus have led to the assumption that this organism 
is not the primary etiological agent in influenza. It cannot be denied, 
however, that it has distinct pathogenic powers; it has apparently 
been isolated from the blood in severe cases by Canon, ^ Bruschet- 
tini,^ and Ghedini,*' at the height of the disease. Slawyk^ has reported 
a case of generalized infection with the influenza bacillus which would 
appear to confirm these results. The report of the Influenza Com- 
mittee upon Influenza in the British Armies in France'^ is also suggestive 
of the etiological relationship of the influenza bacillus to the disease 
influenza. Other observers, however, have questioned these results, 
laying stress upon the apparent incomplete diagnosis of the organism 
obtained from the patient. Lord^ has found influenza bacilli common 
in interepidemic periods as a prominent organism in chronic and acute 
respiratory diseases. Davis has published similar observations.^" 
The earliest presumptive evidence of the etiological relationship 
of B. influenza^ to the disease influenza rested upon a single accidental 
laboratory infection with a pure culture of the organism. The hands 
of an individual were accidentally contaminated with a culture of the 
Pfeifter bacillus and within twenty-four hours a syndrome developed 
which was diagnosed as a typical attack of influenza. The organism 
persisted in the sputum for two months." Davis^- has placed a large 
amount of culture of the Pfeift'er bacillus in a human throat. Fever 
and cough resulted, together with pharyngitis and a muco-purulent 
cough, lasting a month. The organism was readily subcultured. True 
influenza was not produced. Experimental inoculations in army camps 
have also failed to reproduce influenza in volunteer subjects. ^^ 
Foster's^^ work on the filter-passing virus of the "common cold" has 
apparently revived interest in so-called filterable viruses, and Nicolle 
and Lebailly^^ have found that bronchial secretion from influenza patients, 
I Pfuhl: Ztschr. f. Hyg., 1897, 26, 112. Fninkel: Ztschr. f. Hyg., 1898, 27, 315. 
Jundell: Jahrb. f. Kinderheilk., 1904, 59, 777. 
•^ Treitel: Arch. f. Laryngol., 1902, 13, 147. 
'■> Pretori: Arch. f. Augenheilk., 1907, 57, 97. Possek: Wien. klin. W'chnschr., 
1909, 22, 335. 
" Deutsch. med. Wchnschr., 1892, 18, 48; Arch. f. Anat. u. Physiol., 1893, 131, 401. 
5 Riforma med., 1893, 8, 783. « Centralbl. f. Bakteriol., orig., 1907, 43, 407. 
' Ztschr. f. Hyg., 1899, 32, 443. « British Med. Jour., 1919, ii, 851. 
9 Jour. Ani. Med. Assn., 1919, 72, 188. 
10 Proc. Inst. Med. Chicago, 1919, 2, 142. 
11 Tedesco: Centralbl. f. Bacteriol., orig., 1907, 43, 322. 
12 Jour. Infec. Dis., 190.>, 3, 1. » Public Health Reports, 1919, 34, 33. 
" .lour. Infec. Dis., 1917, 21, 451. 
15 Compt. rend. Acad. Sci., 1918, 167, 607; Ann. Inst. Pasteur, 1919, 33, 395. 
