FERMENTS, FERMENTATIONS, AND LIFE. 547 



No doubt, the corpuscles of different species — to which, in the last 

 analysis, we reduce animals and plants of every kind and degree — are 

 not identical. Each species has its own structure, its specific energy, 

 its mode of nutrition, its fixed secretions — characteristics, moreover, 

 which vary with circumstances and media. Yet we can point out 

 more than one interesting similarity between certain ones of these 

 species, which seem to discharge quite distinct functions, and hold 

 very unlike stations, in the vast harmony of vital monads. The cells 

 of fruits, when placed in certain conditions, behave, as has been seen, 

 like the cells of brewer's yeast ; they both decompose sugar and yield 

 alcohol. We may trace resemblances not less close, as M. Blondeau 

 and M. Pasteur have done, between acetic mycoderms and blood- 

 globules. Both alike serve as carriers of oxygen — the first, for the 

 slow combustion of alcohol ; the last, for the slow combustion of the 

 albuminoid matters in animal tissues. It is even likely that there is 

 a principle in mycoderms similar to hemoglobine in the blood- globule, 

 and provided with a special affinity for oxygen. However this may 

 be, comparisons of this kind open a new path for physiology. As that 

 science is definitely summed up in the explanation of existences and 

 processes in the microscopic elements of organs, it is plain that 

 nothing can be more useful to it than the study of these one-celled 

 organisms in which the phenomena are extremely simple, and life is 

 reduced, in a manner, to its primitive factors. It becomes more and 

 more evident that progress in the comprehension of the superior ani- 

 mals is bound, with the very closest ties, to advance in the compre- 

 hension of the mechanism of nutrition in the rudimentary units of life, 

 in the smallest beings that it is given us to study. 



II. 



iN'ow, whence come those organized microscopic corpuscles to 

 which, as we have seen, very many of the alterations of organic mat- 

 ter must be attributed ? Upon this great problem, opinions at this day 

 are still very contradictory. Neither patient observations, nor minute 

 experiments, nor profound reasonings, have been wanting ; yet some 

 still believe that these little bodies grow, by spontaneous generation, 

 within fermentable liquids, while others assert, and profess to have 

 proved, that they come from germs contained in the air. Certainly, 

 the former opinion involves nothing contradictory nor impossible. 

 Those who reject it by begging the question, in the name of some un- 

 known, mystical doctrine of life, do not even deserve to be listened to 

 in the investigation. It might possibly have occurred that organized 

 beings should be produced, complete at all points, in a medium de- 

 prived of organization ; yet experiment proves that this does not 

 occur. "We must, then, accept the other opinion — the panspermist doc- 

 trine — that is to say, we must concede that the germs of microscopic 

 animals and vegetables, with which so many fermentations and putre- 



