BIOGENESIS AND ABIOGENESIS 75 



almost universally held, though, of course, what 

 Pasteur really proved was, not that living matter 

 never arises from non-living matter, but that by 

 observing certain laws and taking the necessary 

 precautions certain substances which would other- 

 wise become invaded by living things which would 

 seize upon them for their food, would be kept 

 intact from them. But as it was the appearance, 

 apparently spontaneously, of life in such substances 

 which had formed the foundation of the theory of 

 spontaneous generation it has often, though in- 

 accurately, been assumed that Pasteur proved 

 that spontaneous generation does not take place. 



Nevertheless the weight of scientific opinion at 

 any rate at the present day is entirely against the 

 possibility or at least the probability of spontaneous 

 generation taking place. A few opinions may now 

 be quoted. 



Tyndall 1 says : " If you ask me whether there Biogenesis 

 exists the least evidence to prove that any form of 

 life can be developed out of matter without demon- 

 strable antecedent life, my reply is ... men of 

 science frankly admit their inability to point to any 

 satisfactory experimental proof that life can be 

 developed save from demonstrable antecedent life." 

 And that he remained of this opinion is shown by 

 a statement four years later: 2 "I affirm that no 

 1 " Belfast Address," 1874. 2 Nineteenth Century, 1878. 



