406 THE BEGINNINGS OF LIFE. 



own experiments 1 tend to show that a ferment may 

 begin to operate, independently of the disturbing in- 

 fluence of oxygen, so long as other conditions are 

 favourable for the initiation of molecular movements 

 amongst its delicately-balanced constituent elements. 



In reference to the doctrine revived by M. Pasteur, 

 that all ferments are living organisms, it should be 

 clearly understood that those who reject this notion 

 by no means deny the almost invariable association of 

 organisms with some fermentations. They maintain 

 however that other real fermentations exist with the 

 occurrence of which organisms are not associated ; and 

 that in all those fermentations in which organisms 

 are encountered, these are concomitant formations or 

 results, rather than causes of the fermentative changes. 

 The facts cited by Pasteur, even granting that his state- 

 ments are perfectly correct, are obviously open to a 

 double interpretation. Although it is true that such 

 constant association of particular organisms with par- 

 ticular fermentations would occur if the changes in 

 question were initiated by pre-existing omnipresent 

 organisms, some of which found in each fermentable 

 substance a nidus suitable for their development and 

 multiplication still the same constancy of association 

 ought also to occur if the changes which initiated the 

 process of fermentation were purely chemical in nature, 

 and led to the evolution of living things as concomitant 



1 In addition to those detailed in the last Chapter, they are recorded 

 in Chapters xii. and xiii., and in Appendix C. 



