148 PHYSIOLOGY OF THE BACTERIA. 
A high power shows them divided into a series of 
shorter rods, scarcely born, not yet mobile at the 
articulations, which are scarcely indicated.” 
2. Micrococcus of a beer, having a_ particular 
acidity, distinct from that of beer piqué, having 
an acetic odor. “It consists of grains resembling 
little spherical points joimted by pairs or im fours 
square ’’ (Pasteur), ete. 
§ 2.— ROLE oF THE BACTERIA IN PUTREFACTION 
AND NITRIFICATION. 
While in the fermentations which we have just 
passed rapidly in review, we have always been 
able to study, at least summarily, the chemical 
action of the different organisms, we are now 
about to find ourselves in presence of phenomena 
far more complex. We will have to consider a 
great number of these vegetables at work, without 
its being possible to assign to each its réle, or to 
say what is its function. The agent of the nitric 
fermentation has not as yet even been seen, and it 
is only by analogy that we class this nitrification 
with the true fermentations. 
It is not only because of the obscurity which 
still exists in regard to a great number of peculiar- 
ities of these two phenomena, that we have united 
them in the same study. From the point of view 
of the circulation upon the surface of our globe 
of the elements essential to the constitution of 
organisms, they play an analogous réle, although 
opposite the one to the other. 
