128 



MICRO-ORGANISMS AND FERMENTATION. 



40 C., and may then rapidly become predominant in sugar 

 solutions if the lactic acid ferment has previously converted 

 a portion of the sugar into lactic acid. This species is decidedly 

 anaerobic. 



A 



t 



Fig. -24.Clogtridium butyricum, Prazm. (after Prazmowski). .4, Vegetative state; c, short 

 rods ; d, long rods ; at a and b, rods and filaments curved like vibriones. B, Formation of 

 "resting spores"; b, d, rods, previous to, c, e, during, f, g, h, after the formation of resting 

 spores ; c, elliptical ; d and h, lemon-shaped ; e, g, spindle-shaped ; f, tadpole-form ; at a rods 

 still in their vegetative state. C, Germination of resting spores ; the spore expands into b ; 

 c, shows the differentiation of the membrane into exo- and endosporium. The contents 

 surrounded by the endosporium issue from the polar fissure of the spore in the form of a short 

 rod (d), which appears prolonged at e. 



Fitz has described a species belonging to the aerobic 

 organisms a bacillus of a short cylindrical form, which is 

 not coloured blue by iodine, is motile in a moderate degree, 

 and forms no spores. It ferments all carbohydrates with 

 the exception of starch and cellulose. 



