iv SPONTANEOUS GENERATION 289 



As accurate enquiries into these matters were made, the 

 number of cases in which equivocal generation was supposed 

 to occur was rapidly diminished. It was not surprising, 

 however, considering the rapidity with which Bacteria and 

 Monads were found to make their appearance in organic 

 substances and infusions, that many men of science imagined 

 them to be produced abiogenetically. The rapid multiplica- 

 tion of these forms means, of course, that a certain amount 

 of fresh living protoplasm has been formed out of the 

 constituents of the hay-infusion, through the agency in the 

 first instance of a single living Bacterium. The question 

 naturally arises, why may not the formation of protoplasm 

 take place independently of this insignificant speck of living 

 matter ? 



It must not be thought that this question is in any way 

 a vain or absurd one. That living protoplasm has at some 

 period of the world's history originated from not-living 

 matter seems a necessary corollary of the doctrine of 

 evolution, and is obviously the very essence of the doctrine 

 of special creation (p. 221) ; and there is no a priori reason 

 why it should be impossible to imitate the unknown con- 

 ditions under which the process took place. But at present 

 we are quite unable to solve this fundamental problem. 



Experiments conducted with proper precautions, however, 

 all tell the same tale : they prove conclusively that in 

 putrescible infusions that have been properly sterilised i.e., 

 thoroughly boiled so as to kill any organisms they may 

 contain and adequately protected from the entrance of 

 atmospheric germs, no micro-organisms ever make their 

 appearance. So that the last argument for abiogenesis has 

 been proved to be fallacious, and the doctrine of biogenesis 

 shown, as conclusively as observation and experiment can 

 show itj to be of universal application as far as existing 



PRACT. ZOOL. U 



