92 EVOLUTION OF THE EARTH 



was the opinion not only of the ignorant and illiterate, but of 

 the most learned grave philosophers of preceding ages; and 

 would probably still have been taught and believed had not 

 microscopes discovered the manner how all these things are 

 generated, and restored to God the glory of his own amazing 

 work." 8 



Although it is relatively easy to follow when one's eyes are 

 opened, it is not to be imagined, of course, that one experiment, 

 or even the long series of studies made by Redi, could annihi- 

 late a time-honored belief. Indeed, the history of the establish- 

 ment of the theory extends down even to the present time, 

 for no sooner had experiment apparently disposed of it com- 

 pletely than it arose again, phoenix-like, with fresh vigor in 

 a slightly different phase demanding further study. 



Among others, a Scotch priest, Turbervill Needham, studied 

 the problem and believed that various minute organisms, 

 which improvements in the microscope were bringing to the 

 fore, appeared spontaneously in infusions which he boiled and 

 corked up in flasks. 9 His results attained considerable noto- 

 riety, since Buffon, the famous French naturalist, found in 

 them a substantiation of his theory that all organisms are 

 aggregates of indestructible units, which upon the death of 

 the individual are disseminated in nature and later are em- 

 ployed as moieties in the organization of arising generations. 



Needham's results, however, were soon shown by Lazzaro 

 Spallanzani 10 to have been obtained by inadequate sterilization 

 and sealing of the infusions which he studied; but at this point 

 objections came from another source the chemists who had 

 recently discovered oxygen and the importance of this element 



8 Baker, H., The microscope made easy, 1742. 



9 Needham, T., A summary of some late observations upon the generation, 

 composition, and decomposition of animal and vegetable substances. Philos. 

 Trans. Roy. Soc. London, 1748. 



10 Spallanzani, L., Experiences pour servir a 1'histoire de la generation des 

 animaux et des plantes, 1786. 



