18971 MICROSCOPICAL JOURNAL. 247 



quently situated in the protoplasm of the pus corpuscles. 

 In fatal case!^ they were found to have penetrated from 

 the bronchial tubes into the peribronchial tissue and even 

 to the surface of the pleura, where in two cases they 

 were found in pure cultures, in the purulent exudation. 



Second. They were found only in cases of Influenza. 

 Numerous control experiments proved their absence in 

 ordinary bronchial catarrh, etc. 



Third. The presence of the bacilli corresponded with 

 Uie course of the disease, and they disappeared with the 

 cessation of the purulent bronchial secretion. 



])urin<^ the past winter I have made a careful examin- 

 ation of the sputum in a number of cases of moderate 

 severity and found a very constant form of bacteria 

 which answers to the moiphological description. 



That the specific exciting cause of Influenza is organic 

 in its true nature and also that the air constitutes the 

 medium of its dissemination there can no longer be any 

 doubt. There is also good reason to believe that an incu- 

 bative stage covering a period of two or three days is 

 necessary for the development of the disease. The micro- 

 organisms are introduced into the upper air passages, 

 and here finding a lodgment, develop upon the epithelial 

 cells where they occur in pure cultures ; they are then 

 drawn into the bronchisG by inhalaticm giving rise to the 

 characteristic sputum, the cough and expectoration fol- 

 lowing in many cases after the patient has recovered 

 from tlie initial symptcans. In this type of the disease 

 little else is sliown by a microscopical examination than 

 the above mentioned bacilli. But in the graver type the 

 picture is quiet different and the severity of the attack is 

 evidently due to a mixed infection. Here we have evi- 

 dence of a local disturbance by tlie great quantities of 

 bronchial epithelia which are thrown off the round cells, 

 are very abundant, and also columnar cells, and often 

 red blood corpuscles. White pus cells are very numerous, 



