The Harvard Classics Volume 38 eBook

This eBook from the Gutenberg Project consists of approximately 554 pages of information about The Harvard Classics Volume 38.

The Harvard Classics Volume 38 eBook

This eBook from the Gutenberg Project consists of approximately 554 pages of information about The Harvard Classics Volume 38.
a vast number of bacteria collect in a thick, moving circle, but as soon as all the oxygen of the bubble has been absorbed they fall apparently lifeless, and are scattered by the movement of the liquid. [Footnote:  We find this fact, which we published as long ago as 1863, confirmed in a work of H. Hoffman’s, published in 1861 under the title of Memoire sur les bacteries, which has appeared in French (Annales des Sciences naturelles, 5th series, vol. ix.).  On this subject we may cite an observation that has not yet been published.  Aerobian bacteria lose all power of movement when suddenly plunged into carbonic acid gas; they recover it, however, as if they had only been suffering from anaesthesia, as soon as they are brought into the air again.]

We may here be permitted to add, as a purely historical matter, that it was these two observations just described, made successively one day in 1861, on vibrios and bacteria, that first suggested to us the idea of the possibility of life without air, and caused us to think that the vibrios which we met so frequently in our lactic fermentations must be the true butyric ferment.

We may pause to consider an interesting question in reference to the two characters under which vibrios appear in butyric fermentations.  What is the reason that some vibrios exhibit refractive corpuscles, generally of a lenticular form, such as we see in fig. 14.  We are strongly inclined to believe that these corpuscles have to do with a special mode of reproduction in the vibrios, common alike to the anaerobian forms which we are studying, and the ordinary aerobian forms in which also 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 fisiparous 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, ready to reproduce others by the process of transverse division for 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 corpuscular 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 suggested 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.

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The Harvard Classics Volume 38 from Project Gutenberg. Public domain.