THEORY OF FERMENTATION . 353 



nary form of minute, soft, exuberant rods, the vibrios perish 

 when submitted to desiccation, but when they occur in cor- 

 puscular or encysted 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 practiced eye cannot detect 

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

 the vibrios 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 sug- 

 gested to us by experiments, 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 of lenticular vibrios, with refractive corpuscles, we 

 observed the fermentation, which for some unknown reason 

 had been very languid, suddenly become extremely active, 

 but now through the influence of the ordinary vibrios. The 

 gemmules with brilliant corpuscles had almost disappeared; 

 we could see but very few, and those now consisted of the 

 refractive bodies alone, the bulk of the vibrios accompanying 

 them having undergone some process of re-absorption. 



Another observation which still more closely accords with 

 this hypothesis is given in our work on silk-worm disease 

 (vol. i, p. 256). We there demonstrated that, when we 

 place in water some of the dust formed of desiccated vibrios, 

 containing a host of these refractive corpuscles, in the 

 course of a very few hours large vibrios appear, well-devel- 

 oped rods fully grown, in which the brilliant points are 

 absent; whilst in the water no process of development from 

 smaller vibrios is to be discerned, a fact which seems to show 

 that the former had issued fully grown from the refractive 

 corpuscles, just as we see colpoda issue with their adult 

 (12) HC xxxvin 



