X. 

 BACTERIA IN INFLUENZA. 



A NUMBER of bacteriologists have made careful researches during 

 the recent extended epidemic of influenza, and quite recently (1892) 

 a bacillus has been discovered, both by Pfeiffer and by Canon, of 

 Berlin, which there is good reason to believe is the specific cause of 

 this disease. Before describing this we shall refer briefly to previous 

 researches. 



Babes has described no less than seventeen distinct species or varieties 

 isolated by him, principally from nasal or bronchial mucus. Among these 

 a considerable number closely resemble Streptococcus pyogenes or Micro- 

 coccus pneumoniae crouposae. No one form was found with sufficient con- 

 stancy to justify the inference that it was the specific cause of the disease. 



Klebs, in examining blood drawn from the fingers of patients with influ- 

 enza, observed an enormous number of small, actively motile, highly refrac- 

 tive bodies, which in their size, form, and movements corresponded entirely 

 with similar bodies previously observed by him in the blood of patients with 

 pernicious anaemia, but which were far more numerous. These bodies are 

 believed by Klebs to be flagellate infusoria ("flagellata"). The investiga- 

 tions of other bacteriologists have not thus far confirmed those of Klebs as 

 regards the presence of microorganisms of this class in the blood of patients 

 with influenza. 



Kowalski, who made bacteriological researches in sixteen cases, was not 

 able to find microorganisms of any kind in the blood, examined both fresh 

 and in dried preparations. In his cultures from the nasal, buccal, and 

 bronchial secretions of the sick he obtained in five cases Staphylococcus 

 pyogenes aureus, in four Staphylococcus pyogenes albus, in two "diplococ- 

 cus pneumoniae," in two Streptococcus pyogenes, in two Staphylococcus 

 pyogenes citreus, in one Friedlander's bacillus, in one Staphylococcus cereus 

 albus, in one Staphylococcus cereus flavus. In addition to these he isolated 

 three species not previously described. One of these he found in seven 

 cases ; this grew upon the surface of agar as small, transparent drops, but 

 did not grow upon potato, in sterilized milk, or in bouillon ; it was a coccus 

 arranged in pairs or in chains, and is designated by Kowalski " Gallertstrep- 

 tococcus." 



Prior, in a bacteriological study of fifty- three cases, twenty-nine of which 

 were without complication and twenty-four complicated by pneumonia, 

 found in the sputum of uncomplicated cases, as the most abundant and com- 

 mon microorganism at the outset of the attack, Micrococcus pneumoniae 

 crouposae ; next to this came Staphylococcus pyogenes aureus and Strepto- 

 coccus pyogenes ; when the acme of the attack was past the two species first 

 named quickly diminished in numbers, while streptococci were found for a 

 longer time. In cases of croupous pneumonia following influenza " diplo- 

 coccus pneumoniae " was constantly found in great numbers. 



Fiscnel (1891) obtained in cultures from the blood of two cases two dif- 



