CLOSTRIDIUM BUTYRICUM. 



187 



ing heat possessed by the endospores of CL butyricum was examined 

 by Prazmowski. They are able to remain in boiling water for five 

 minutes without injury ; but if the treatment be prolonged to twice 

 that duration, then only the hardiest spores of all are left alive, and 

 even these succumb if the boiling be extended to fifteen minutes. 

 The progress of the germination of the endospores has already 

 been described in 57 (q.v.). The brisk locomotion of the rods 

 is produced by a large number of cilia, shown in Fig. 50. Praz- 

 mowski did not have pure cultures, in the present acceptance of 

 the term, at disposal for his researches, but was obliged to confine 

 himself to an approximately pure culture prepared by means of 

 Roberts' boiling method ( 107). The same remark applies to a 



FIG. 49. Clostridium butyricum. 



Vegetative forms of growth ; short rods of dif- 

 ferent lengths, partly straight (c, d ), partly 

 curved (a, 6). Magn. 1020. (After Praz- 

 mowski.) 



FIG. 50. 



Clostridium butyricum. 

 With endospore. 



Stained cilia. Magn. 2000. 

 (After A. Fischer.) 



valuable treatise by A. FITZ (VII. ), wherein the fermentative 

 activity of a fission fungus named Bacillus butylicus is reported 

 upon. 



After E. Ch. Hansen, in 1878-79, had established, in connec- 

 tion with acetic fermentation, the new and important fact that 

 this decomposition process is effected by at least two different 

 species of bacteria, F. HUEPPE (IV.) in 1884 found the same to 

 be the case with butyric fermentation and discovered a Bacillus 

 butyricus which exerted its decomposing activity in presence of 

 air. This fact was confirmed by MAX GRUBER (II.), working with 

 a reliable method of pure culture in 1887, and it was at the same 

 time demonstrated that the Clostridium butyricum of Prazmowski 

 consists of a number of closely allied, but nevertheless distinct, 

 species. Nearly related to this is a ferment isolated by P. 

 LIBORIUS (I.) from old cheese, and introduced into literature 

 under the name of Clostridium foetidum. This organism liberates 

 very foul-smelling gases, in addition to producing butyric acid, 



