134 THE CASE AGAINST EVOLUTION 



interpretation of natural facts, which was universally accepted 

 up to the close of the 17th century. As we can do no more 

 than recount a few outstanding incidents of its long and in- 

 teresting history here, the reader is referred to the VII chapter 

 of Wasmann's "Modern Biology" and the VIII chapter of 

 Windle's ^'Vitalism and Scholasticism" for the details which 

 we are obliged to omit. 



§ 2. The Law of Genetic Continuity 



From time immemorial the sudden appearance of maggots 

 in putrescent meat had been a matter of common knowledge, 

 and the ancients were misled into regarding the phenomenon 

 as an instance of a de novo origin of life from dead matter. 

 The error in question persisted until the year 1698, when it was 

 decisively disproved by a simple experiment of the Italian 

 physician Francesco Redi. He protected the meat from flies 

 by means of gauze. Under these conditions, no maggots ap- 

 peared in the meat, while the flies, unable to reach the meat, 

 deposited their eggs on the gauze. Thus it became apparent 

 that the maggots were larval flies, which emerged from fer- 

 tilized eggs previously deposited in decaying meat by female 

 flies. Antonio Vallisnieri, another Italian, showed that the 

 fruit-fly had a similar life-history. As a result of these dis- 

 coveries, Redi rejected the theory of spontaneous generation 

 and formulated the first article of the Law of Genetic Vital 

 Continuity: Omne vivum ex vivo. 



Meanwhile, the first researches conducted by means of the 

 newly invented compound microscope disclosed what appeared 

 to be fresh evidence in favor of the discarded hypothesis. The 

 unicellular organisms known as infusoria were found to ap- 

 pear suddenly in hay infusions, and their abrupt appearance 

 was ascribed to spontaneous generation. Towards the end 

 of the 18th century, however, a Catholic priest named Lazzaro 

 Spallanzani refuted this new argument by sterilizing the infu- 

 sions with heat and by sealing the containers as protection 

 against contamination by floating spores or cysts. After the 



