306 STUDIES ox FERMENTATION. 



such as we see in Fig. 72 ? We are strongly inclined to believe 

 that these corpuscles have to do with a special mode of repro- 

 duction in the vibrios, common alike to the anaurobian forms 

 which we are studying, and the ordinary aerobian forms in 

 which alsu the corpuscles of which we are speaking may occur. 

 The explanation of the phenomenon, from our point of view, 

 would be that, after a certain number of fissiparous generations, 

 and under the influence of variations in the composition of the 

 medium, which is constantly changing through fermentation as 

 well as through the active life of the vibrios themselves, cysts, 

 which are simply the refractive corpuscles, form along them at 

 different points. From these gemmules we have ultimately 

 produced vibrios, read}' to reproduce others by the process of 

 transverse division lor a certain time, to be themselves encysted 

 later on. Various observations incline us to believe that, in their 

 ordinary form of minute, soft, exuberant rods, the vibrios 

 perish when submitted to desiccation, but when they occur in 

 the corpuscular or encj^sted form they possess unusual powers 

 of resistance, and may be brought to the state of dry dust and be 

 wafted about by winds. None of the matter which surrounds 

 the corpuscle or cyst seems to take part in the preservation of 

 the germ, when the cyst is formed, for it is all re-absorbed, 

 gradually leaving the cyst bare. The cysts appear as masses of 

 corpuscles, in which the most practised eye cannot detect any- 

 thing of an organic nature, or anything to remind one of the 

 A'ibrios which produced them ; nevertheless, these minute bodies 

 are endowed with a latent vital action, and only await favourable 

 conditions to develop long rods of vibrios. We are not, it is 

 true, in a position to adduce any very forcible proofs in support 

 of these opinions. They have been suggested to us by experi- 

 ments, none of which, however, have been absolutely decisive 

 in their favour. We may cite one of our observations on this 

 subject. 



In a fermentation of glycerine in a mineral medium — the 

 glycerine was fermenting under the influence of butyric vibrios 

 — after we had determined the, we may say, exclusive presence 



