BACTERIOLOGY OF WHOOPING-COUGH 



pertussis bacillus, and sparsely with some other organism, such as 

 staphylococcus. In 24 hours the symbiotic relationship is usually 

 evident. 



If pertussis sputum containing large numbers of the influenza-like 

 bacilli, as it commonly does, is spread on plain agar or Loeffler's 

 blood-serum, these bacilli will often grow in abundance. Other 

 germs are always present under these circumstances, and undoubtedly 

 their growth has much to do in causing the influenza-like bacilli to 

 develop on the hemoglobin-free media; for, in sterile sputum alone, 

 the latter do not grow. If transferred thus in impure culture upon 

 plain media, they often survive several generations, and their growth 

 may be easily determined by making blood- agar plates at the time 

 of each transplantation. It was practically this technique that 

 Czaplewski and Hensel, and others who obtained similar results 

 later, used to isolate their bacillus, and one is strongly tempted to 

 believe that they have thus been cultivating in impure culture the 

 same hemophilous bacillus found by Spengler and Jochmann. As 

 already stated, this was Spengler's explanation of their results. Such 

 an interpretation seems far more reasonable than the possibility that 

 Czaplewski's organism, found as frequently as he reported, was an 

 entirely different organism from the hemophilous bacillus found by 

 so many. 



The growth of the several strains of influenza-like bacilli from 

 pertussis was tested upon various media, to which were added dead 

 bacteria (staphylococci, streptococci) and filtrates of cultures; the 

 results were uniformly negative. All of the experiments performed 

 indicated that the symbiosis is dependent on the presence of the 

 living organisms. 



The symbiotic relation of other bacteria to the influenza-like 

 organisms is shown by the increased pathogenicity of the latter for 

 animals. This will be more fully discussed under the head of animal 

 experiments. 



IV. ANIMAL EXPERIMENTS. 



Literature. The results obtained by the inoculation of whooping- 

 cough virus into animals by various investigators have for the most 

 part been negative. The older reports of producing the disease in 

 dogs can hardly be considered seriously. Afanassiew reported that 



