346 IMPORTANT VARIETIES OF FISSION-FUNGI. 



vestigated the zymogenic activities of the varieties isolated 

 by them for purposes of differential diagnosis, whereby 

 typical production of butyric acid was demonstrated in 

 a number of varieties, also the ferment technicians have 

 studied the anaerobic varieties as to their ability to form 

 butyric acid, and have considered their pathogenic func- 

 tions only secondarily or not at all. 



We have not been able to study this group more closely, 

 and cannot refer to the extensive literature in the absence 

 of any comprehensive reviews, l but look forward to the 

 exhaustive publication by v. Hibler. A review was sup- 

 plied by Baier in 1895 (C. B. L. i, 17). 



The following was found in Fliigge's laboratory to be a 

 vigorous anaerobic producer of butyric acid. 



Bacillus butyricus. Botkin. (Z. H. xi, 421.) 



Microscopically : Rods 1 to 3 /u long, 0.5 // thick, often in chains in 

 fluid nutrient media. They are motile and stain by Gram's method. 

 The spores are in the middle or at the end, about 1 // thick and are 

 formed only upon non-saccharine media. Obligate anaerobe. Opti- 

 mum temperature is 37. Upon sugar-agar the growth appears like 

 that of the other described anaerobes. Upon sugar-gelatin the col- 

 onies possess a slightly undulating border, as if consisting of a mass 

 of felted threads, without the formation of branches. Gelatin is 

 rapidly liquefied. After fifteen hours the casein of milk is precipi- 

 tated, and butyric acid is formed, with violent liberation of gas; later 

 the coagulum is soon dissolved. Upon nutrient media containing 

 starch the bacillus presents inclosures staining with iodin. Starch is 

 converted into sugar, and this directly into butyric acid. Also butyric 

 acid is produced from milk-sugar without an intermediate formation 

 of lactic acid. The organism is widely distributed and supposed to be 

 non-pathogenic. The following may perhaps appear as a pathogenic 

 form of this organism. 



Bacillus sporogenes. (Klein.) L. and N. 



Bacillus enteritidis sporogenes Klein (C. B. xvm, 737; 

 xxii, 113, 577; xxv, 278). 



This rather strictly anaerobic organism stands very 

 close to the Bacillus butyricus Botkin (see above), espe- 

 cially as regards the appearance, staining properties 



1 Regarding Clostridium butyricum Prazmowski, see also v. Hibler, 

 7. c. Regarding Clostridium butyricum M. Gruber I and II, see C. B. 

 I, 367. 



