96 Scientific Sophisms. 



thesis that all living matter has sprung from 

 pre-existing living matter, he traces not to our 

 great countryman, Harvey, but to a contem- 

 porary though a junior of Harvey, and trained 

 in the same schools, Francesco Redi. And he 

 concludes his sketch of the progress of the 

 doctrine, and of the successive experiments by 

 which its truth has been established, in these 

 words : " So much for the history of the progress 

 of Redi's great doctrine of Biogenesis, which 

 appears to me, with the limitations I have 

 expressed, to be victorious along the whole line 

 at the present day." * 



His own adhesion to this "great doctrine of 

 Biogenesis " is thus stated : " If in the present 

 state of science the alternative is offered us, 

 cither germs can stand a greater heat than has 

 been supposed, or the molecules of dead matter, 

 for no valid or intelligible reason that is as- 

 signed, are able to rearrange themselves into 

 living bodies, exactly such as can be demon- 

 strated to be frequently produced another way, 

 I cannot understand how choice can be, even 

 for a moment, doubtful. 



" But though I cannot express this conviction 

 of mine too strongly, I must carefully guard 

 myself against the supposition that I intend to 

 1 " Critiques and Addresses," p. 239. 



