SPONTANEOUS GENERATION 195 



imagined. For, when spontaneous generation appar- 

 ently takes place, it can be maintained that pre- 

 viously existing life still remained, when the results 

 are negative, as in the case of Pasteur's experiments, 

 the opposition has a stronger case because no doubt 

 the conditions under which life could have been 

 originated might, in the circumstances or con- 

 ditions under which the experiment was made, 

 have been sufficient to prevent the phenomenon 

 from taking place. Furthermore, even if the 

 conditions are not such as to prevent a reappear- 

 ance of life, that reappearance may take many 

 years or centuries or, forsooth, aeons in which to 

 assert itself. And thus such experiments cannot, 

 strictly speaking, be regarded in either case as 

 quite conclusive. 



When, however, such forms as may reappear in 

 experiments with positive results are totally 

 diflferent from anything that may have existed 

 therein beforehand, there surely is no room for 

 inference other than that of the transmutation of 

 some germ or germs not totally destroyed ; or, if 

 destroyed, of course the spontaneous development 

 of something new. Between these, it is not easy, 

 even if it should be possible, to decide. 



The subject of spontaneous generation has been 

 perennially discussed, and by none more consistently 

 than by Dr. Bastian since his work on the Beginnings 

 of Life, already alluded to, was published more 

 than thirty years ago, as well as amongst other 

 works in his studies of heterogenesis published 

 in 1903. He has pleaded, and pleaded strongly, in 



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