390 



ACETIC FERMENTATION. 



that, at all temperatures higher than 5 C. (but not greatly ex- 

 ceeding 34 C.), chains of short rods develop, which, when grown 

 at temperatures below 15 C., often attain extraordinary dimen- 

 sions, especially in the direction of the breadth. The formation 

 of chains proceeds most abundantly at about 34 C., the individual 



FIG. 86. Bacterium Pasteurianum. 



Conversion of long threads into swollen (bulged) forms and chains. Culture in " doppel- 

 bier " at 34 C. I. condition after four hours ; II. after five he 



hours. Magn. 1000. (After Ilansen.) 



five hours ; III. after seven 



short rods then having the ordinary form and being filled with 

 firm, slightly lustrous plasma. 



If a small portion of such a skin, cultivated at 34 C., be 

 transferred to a fresh nutrient medium, and maintained at 

 4o-4o.5 C., a morphological alteration of the cells (Fig. 84) 



