150 THE EVOLUTION OF LIFE 
3rd Flypothests. The fertelsing agent acts by 
helping to inrteate chemical changes of a fermentative 
character in a flued devoid of living organisms or 
living germs. If fermentation occurs in the absence 
of living units, then it must be occasioned by some 
chemical reactions set up between the boiled liquor 
potassee and the boiled urine; and these experi- 
ments would seem to prove that living matter may 
and does originate independently during the progress 
of fermentation in certain fluids—since, in the ex- 
periments in question, swarms of Bacteria make 
their appearance in the fluids employed. 

