WHOOPING COUGH. 415 



microbes in abundance, and produces the disease when 

 inoculated into healthy pigeons. . . . 



44 In a certain number of pigeons the cutaneous erup- 

 tion is wanting, and in this case the autopsy reveals a 

 veritable intestinal pustulation. 



44 The microbes from the pustules or from the blood, 

 cultivated in pigeon bouillon, have furnished successive 

 culture-liquids which, when inoculated, reproduce the 

 disease. 



44 But it is the blood (in vitro) and the lymph which 

 are the best culture media for the microbes of variola, 

 either of man or of the lower animals. And neverthe- 

 less, if we examine the blood of subjects attacked with 

 variola (man, the pig) we find that it contains but few 

 microbes, so that it is difficult to suppose that these or- 

 ganisms are the first cause of the malady. So also in 

 charbon, in many animals but few bacteries are found in 

 the blood at the moment of death. This is because, 

 in the living animal, the most favorable medium for 

 the development of these infectious organisms is the 

 lymph. Numerous observations enable us to affirm 

 this fact. . . . 



44 In conclusion we will say that if the microbes in the 

 course of an infectious malady do not multiply in the 

 blood in circulation, they are susceptible of multiplica- 

 tion in the blood in repose, drawn directly from an 

 artery into Pasteur's flasks sterilized, and that they 

 retain their specific qualities." 



WHOOPING COUGH. 4t Poulet, in 1867, found certain 

 bacteria of a peculiar kind in the sputa of patients affected 

 with pertussis ; Letzerich commenced a series of investi- 

 gations a few years later. The latter found constantly 

 present in the sputum of pertussoid patients a bacterium 

 belonging to the genus Ustiligo, Tul. ; with this he 



