96 THE GROUSE DISEASE chap. 



translucent film with sinuous margin ; after about a 

 week it has spread almost over the whole surface of 

 the Agar, but it remains a thin film. 



Equally marked differences between the bacillus, 

 of fowl cholera and fowl enteritis are shown by their 

 behaviour on potato ; while the bacillus of fowl cholera 

 shows distinct growth on boiled or steamed potato, as 

 has been described in a former chapter, the bacillus of 

 fowl enteritis practically does not grow on potato — 

 even after a week at 35-37° C. incubation the point of 

 inoculation is only just perceptible as a whitish patch ; 

 of anything like an appreciable amount of growth 

 nothing is to be made out. 



As regards aspect and size of the bacilli of fowl 

 enteritis there is not much to be added to what has 

 been said already ; in all media the bacilli are either 

 oval or rod- or cylindrical-shaped organisms, either 

 single or in dumb-bells, their ends rounded, and when 

 examined fresh in salt solution or in broth, never show- 

 ing motility. Their length, however, varies somewhat 

 in gelatine and Agar cultures. Cover-glass impression- 

 preparations of gelatine plate cultivations, dried and 

 stained, show that in some colonies the bacilli are 

 conspicuously more cylindrical than in others. Fig. 48 

 is a photograph taken from an impression specimen of 

 a colony on the surface of a gelatine plate, and here 

 the bacilli are all conspicuously cylindrical, so much so 



