THE GENESIS OF LIFE. 



SOME two hundred years or more ago, the savants of 

 Florence were somewhat startled by the declaration of one 

 of their number that he had found cause to disagree with 

 the universally received ideas regarding the origin of living 

 beings, ideas, the correctness or validity of which had till 

 then been unquestioned and undoubted. The man who 

 played in Florence the part of a seventeenth-century reformer 

 was Francesco Redi, a well-known philosopher-physician, 

 esteemed in his day and generation as an able and con- 

 scientious observer of biological phenomena. The subject 

 to which he especially directed the attention of his scientific 

 brethren was that of the origin and production of insects, 

 and more especially of those insects which, like the familiar 

 maggots, appear in animal and vegetable substances under- 

 going changes of a putrefactive nature. From the investiga- 

 tion of an apparently trifling and unsavoury subject, as we 

 shall presently note, results of the highest importance may 

 sometimes spring; and it may be truly affirmed that the 

 subject mooted in Florence two hundred years ago has 

 come to constitute one of the most important scientific 

 questions, if not the paramount one, of the nineteenth cen- 

 tury. Prior to Francesco Redi's day, the opinion of philo- 

 sophers regarding the origin of many lower animals was 

 perfectly uniform and consistent. They held not only that 

 it was possible for living things even of tolerably high grade 

 to spring from non-living material, but that nature frequently 

 produced both animals and plants in this way. Selecting,, 



