68 THE GROUSE DISEASE chap. 



flat gas bubbles appear all through the gelatine, one 

 in connection with each individual colony, except 

 in the superficial layers ; the gas bubbles situated 

 in the depth remaining longest ; in respect of these 

 gas bubbles no difference is noticeable between the 

 two species. On potato the difference noticeable 

 between the two microbes is this, that the oedema 

 bacillus grows faster and spreads out quicker over the 

 surface of the potato than the grouse bacillus, the former 

 producing a more brownish growth than the latter. 



As regards the morphological appearances, the 

 gelatine and Agar cultures of our malignant oedema 

 bacillus, examined fresh, show more motile forms 

 than the cultures of the grouse bacillus, and the 

 individual bacilli are distinctly longer and more 

 cylindrical — both in the animal and in the culture — 

 in the case of our malignant oedema than in the 

 case of the grouse bacillus ; this is a definite and 

 constant difference easily detected. 



Measurements of the bacilli of our malignant 

 oedema in dried and stained cover-glass specimens, 

 show : — 



In the oedematous fluid of the guinea-pig : 

 Thickness 0.7 /^ 

 The majority in length 0.8-1.2 yu 

 Some ,, ,, 1.6-2,4 /^ 

 Few up to . . 2.4 yu long. 



