BACILLUS BUTYRICUS (PRAZMOWSKI.) 367 



bacilli of greenish-blue pus from glycerine, &c.). Pasteur, Butyric acid 

 Prazmowski, Fitz, and Hueppe have each described c |ed by " 



bacilli which cause butyric fermentation, but which y-anons 



bacteria. 

 according to the descriptions as yet given are not 



the same species in each case, although some of them 

 have not been sufficiently accurately studied to enable 

 us to come to a conclusion as to their identity. Accord- 

 ing to investigations in the author's laboratory the 

 number of butyric acid bacilli is probably very con- 

 siderable ; but the majority of these, on account of the 

 fact that they are anaerobes and cannot be isolated and 

 cultivated pure by the ordinary methods of cultivation, 

 present such great difficulties in their diagnosis that 

 we must await further investigations in order to 

 obtain an accurate knowledge of these forms. In the 

 following description we shall take as our basis the 

 description of the butyric acid bacillus given by Praz- 

 mowski, which corresponds fairly well with that of 

 Pasteur and van Tieghem, but which has not been 

 based on pure cultivations ; secondly, we may describe 

 for the present as a separate species an anaerobic 

 bacterium, the characteristics of which have been 

 studied by Liborius in the author's laboratory with 

 regard to its fermentative activity, accurate analyses 

 are wanting, but it is possibly identical in its mor- 

 phological and biological characters with Prazmowski's 

 organism ; and in the third place we must mention 

 the bacillus isolated by Hueppe from milk, and which 

 differs in an important manner from those previously 

 mentioned on account of its aerobic properties. 



Bacillus bufyricus (PRAZMOWSKI). 



This organism presents the form of rods 3 to 10 /*. l. Prazmow- 

 in length, and 1 /*., or somewhat less, in breadth. It acid bac jfus. 

 frequently forms chains, or apparently threads, which 

 have not undergone segmentation. It is usually 

 actively mobile, but at times it is at rest and forms 

 zooglcea. After some time the rods cease to grow in Morphological 

 length and increase in thickness ; the shorter rods c 

 increase in thickness chiefly in their middle, and 



