244 BIOGENESIS AND ABIOGENESIS \m 



therefore must be classified under Xenogenesis, 

 rather than under Abiogenesis. Such as it was, I 

 think it will appear, to those who will be just 

 enough to remember that it was propounded 

 before the birth of modern chemistry, and of the 

 modern optical arts, to be a most ingenious and 

 suggestive speculation. 



But the great tragedy of Science — the slaying of 

 a beautiful hypothesis by an ugly fact — which is so 

 constantly being enacted under the eyes of philo- 

 sophers, was played, almost immediately, for the 

 benefit of Buff on and Needham. 



Once more, an Italian, the Abbt^ Spallanzani, a 

 worthy successor and representative of Redi in his 

 acuteness, his ingenuity, and his learning, sub- 

 jected the experiments and the conclusions of 

 Needham to a searching criticism. It might be 

 true that Needham's experiments yielded results 

 such as he had described, but did they bear out 

 his arguments ? Was it not possible, in the first 

 place, he had not completely excluded the air by his 

 corks and mastic ? And was it not possible, in the 

 second place, that he had not sufficiently heated 

 his infusions and the superjacent air ? Spallan- 

 zani joined issue with the English naturalist on 

 both these pleas, and he showed that if, in the first 

 place, the glass vessels in which the infusions were 

 contained were hermetically sealed by fusing their 

 necks, and if, in the second place, they were ex- 

 posed to the temperature of boiling water for 



