ORIGIN OF LO WES T OR GA NISMS. 3 1 



we are really still in the region of hypothesis no 

 further advanced than we were in the time of Bonnet 

 and of Spallanzani, so far as it concerns the organisms 

 which are all important Bacteria. Neither these 

 nor their germs have been shown to exist in any 

 recognizable abundance in the atmosphere, and yet 

 in most fermentations they are the first organisms 

 which display themselves ; whilst in many such 

 fermentations Bacteria alone occur. Nay more, even 

 were they present in any great abundance, there is 

 some reason to believe that the majority of them 

 would exist as mere dead, organic particles because 

 Bacteria are more than likely to be unable to resist 

 anything like an extreme or prolonged exposure to 

 desiccating influences. 



The first and essential data in support of M. 

 Pasteur's hypothesis must, therefore, be regarded as 

 entirely unproved in respect to Bacteria which are 

 the most important of all organisms, in relation to 

 the cause of fermentation and putrefaction. 



Without the aid of elaborate experiments, however, 

 the evidence which the microscope can supply is 

 capable of leading us to the conclusion that such 

 search for atmospheric Bacteria germs, was com- 

 paratively useless. If it can be shown that Bacteria 

 can arise in a fluid independently of visible germs, 

 then, obviously, any inquiries as to the nature of the 

 visible contents of the atmosphere, can have only a 

 very indirect bearing upon the question as to the 



