116 STUDIES ON FERMENTATION. 



under our eyes all the characteristics of a yeast, which, beyond 

 doubt, would give rise to a very active fermentation, inasmuch 

 as it would belong to the order of phenomena of nutrition and 

 vital energy of which we are speaking. Instead, however, of 

 insisting upon the acceptance of our interpretations, based on a 

 few facts merely, let us go on to accumulate facts, varying the 

 conditions as much as possible. Our examples, taken singly, 

 may seem insufficient to establish the theory that it will be our 

 endeavour to substantiate, but taken together we trust that they 

 will secure our readers' confidence. 



We may now, perhaps with advantage, introduce two new 

 expressions to embody the preceding facts, by the help of which 

 we may often shorten our subsequent explanations. Since life 

 can continue, under certain conditions, away from contact with 

 the oxygen of the air, and since the altered nutrition is accom- 

 panied by a phenomenon which is of great scientific as well as 

 industrial importance, we may divide living beings into two 

 classes, aerobian, that is those which cannot live without air, 

 and anaerobian, which, strictly speaking, and for a time, can do 

 without it ; these latter would be ferments, properly so called. 

 Again, since we can conceive, in an entire organism, some organ 

 or even a cell capable of existing, at least momentarily, apart from 

 the influence of the air, and endowed at a given moment with the 

 character of a ferment, we may, in like manner, make use of the 

 expression anaerobian cell, in opposition to a cell that is aerobian. 



As long ago as 1863, in our work on putrefaction, we pro- 

 posed to adopt the preceding expressions, and since then we 

 have had the satisfaction of seeing them used by different authors 

 in France and other countries. 



One of the principal assertions in this paragraph relates to 

 the non -transformation of mycoclerma vini into other moulds or 

 into yeast.* 



For a long time, like Turpin and many other observers, although 

 we had no belief in the transformation oi mycoclerma vini mio any 



* In a subsequent chapter we shall prove that j'east is likewise in- 

 capable uf trausformatiou into mycodernui vini. 



