QUESTIONS. 175 



Biologic Characters. The bacillus of influenza is strictly 

 aerobic, not growing at all without oxygen. It is non-motile, 

 and grows at a temperature between 26 and 43 C. 



It grows but rather poorly in all media that may be sub- 

 mitted to this temperature, unless the surface of the media 

 be smeared over with fresh sterilized blood, when the growth 

 is quite luxuriant. On glycerin-agar or in blood-serum tubes 

 on which fresh rabbit's blood has been smeared, it grows as 

 transparent watery colonies, resembling very much dew- 

 drops. The colonies have no tendency to coalesce. In 

 bouillon to which a little fresh blood has been added it grows 

 luxuriantly. It does not cause clouding of the medium, but 

 its colonies are seen as little flakes adhering to the sides of 

 the tube and forming a deposit at the bottom. 



Vitality. The bacillus of influenza is destroyed in two or 

 three hours by drying. It has very little resisting power, 

 and in water lives scarcely twenty-four hours. In pneu- 

 monia occurring during the course of this disease the bacilli 

 are often found in the body of the leucocytes. 



Pathogenesis. Outside of the human race none of the 

 lower animals seems to be susceptible to the disease, excepting 

 perhaps the monkey, and by inoculation it is difficult to 

 produce any symptom in laboratory animals. In man, how- 

 ever, the bacillus is constantly found in the bronchial and 

 nasal secretions, also in the pneumonic patches so often found 

 in the course of this disease. At autopsies it has been found 

 also in the spleen and occasionally in the blood. Some per- 

 sons have a natural power of retaining live bacilli in the 

 lungs for a considerable length of time ; especially is this the 

 case with tuberculous patients, in whose sputum is very often 

 found the Bacillus influence. By inoculating animals in the 

 brain, the nervous phenomena of this disease have been 

 easily reproduced. 



QUESTIONS. 



By whom and when was the bacillus of influenza discovered ? 



Describe this bacillus and its staining peculiarities? 



Does it possess flagella ? Spores ? 



What are the principal biologic characters of the bacillus of influenza? 



