54 THE LAND-MARKS OF 



^Re'dr" IVf ^-^^ ^^^^ *^° hundred years have elapsed 

 -^'-'- since Francesco -Redi — " a man of the 

 widest knowledge and most versatile abilities, 

 distinguished alike as scholar, poet, physician, and 

 naturalist " (Huxley) " and the originator of the 

 doctrine of Biogenesis — first gave to Europe the 

 result of his investigations into the nature of 

 the venom of the viper. Previous to his time 

 the grossest ignorance prevailed not only regard- 

 ing the nature of the poison, but even as to the 

 organ by which the snake inflicted its deadly 

 injuries. It is true this great man did little 

 more than correct the principal fallacies which 

 prevailed ; still, he it was who first directed men's 

 minds to the subject, and collected by patient en- 

 quiry, the crude material which Fontana, a 

 century later, moulded into something like 

 definite shape. 



Physiology has, thanks to Chemistry and 

 Mechanical Art, made rapid progress. For 

 example, the theory of " omne vivum ex ovo " 

 which was only very roughly demonstrated by 

 Redi, is now demonstrated (and by many con- 

 sidered positively proved by the most elaborate 

 processes. What was in Redi's time a rough 

 outline is now a well-filled-in picture, not quite 



