THE BACILLUS OF WHOOPING-COUGH. 613 



not yellow fever. According to them the lungs were 

 the earliest and the chief seat of the lesions. Their 

 report adds to the mystery of the effect of cold on 

 stopping the spread of the disease, for nearly all respi- 

 ratory diseases due to bacteria tend to increase in cold 

 weather, and certainly their spread is not stopped im- 

 mediately. This bacillus can as yet be considered as 

 only the possible cause of yellow fever. 



THE BACILLUS OF WHOOPING-COUGH. 



From lime to time observers have found in the 

 sputum of persons suffering from whooping-cough 

 small bacilli, often in great numbers. These have been 

 studied lately especially by Koplik 1 and Czaplewski 2 

 and Hensel, who believe that these bacilli are the cause 

 of the disease. They are small bacilli of about the size 

 of the influenza bacillus, and grow on blood-serum and 

 nutrient agar in tiny colonies. Mice and rabbits die 

 after intravenous inoculations. No symptoms similar 

 to those in man are noted. The observers differ as to 

 the description of the bacilli, and those interested are 

 referred to the original articles. The examination for 

 these bacilli, if they prove to be the true cause of the 

 disease, may prove of diagnostic importance, and also 

 be of use in detecting sources of contagion. 



i Centralblatt fur Bact. Abth., 1 Bd. 22, p. 222 * Ibid., p. 641. 



