SPONTANEO US KNERA TIOJS. 563 



hesitation I jumped to the conclusion that these maggots 

 had been spontaneously generated in the meat. I had no 

 knowledge which could qualify or oppose this conclusion, 

 and for the time it was irresistible. The childhood of the 

 individual typifies that of the race, and the belief here 

 enunciated was that of the world for nearly two thousand 

 years. 



To the examination of this very point the celebrated 

 Francesco Redi, physician to the Grand Dukes Ferdinand 

 II. and Cosmo III. of Tuscany, and a member of the Acad- 

 emy del Cimento, addressed himself in 1668. He had seen 

 the maggots of putrefying flesh, and reflected on their 

 possible origin. But he was not content with mere reflec- 

 tion, nor with the theoretic guesswork which his pred- 

 ecessors had founded upon their imperfect observations. 

 Watching meat during its passage from freshness to decay, 

 prior to the appearance of maggots he invariably observed 

 flies buzzing round the meat and frequently alighting on 

 it. The maggots, he thought, might be the half-developed 

 progeny of these flies. 



The inductive guess precedes experiment, by which, 

 however, it must be finally tested. Redi knew this, and 

 acted accordingly. Placing fresh meat in a jar and cover- 

 ing the mouth with paper, he found that, though the 

 meat putrefied in the ordinary way, it never bred maggots, 

 while the same meat placed in open jars soon swarmed with 

 these organisms. For the paper cover he then substituted 

 fine gauze, through which the odor of the meat could rise. 

 Over it the flies buzzed, and on it they laid their eggs, but, 

 the meshes being too small to permit the eggs to fall 

 tli rough, no maggots were generated in the meat. They 

 wore, on the contrary, hatched upon the gauze. By a 

 series of such experiments Redi destroyed the belief in the 

 spontaneous generation of maggots in meat, and with it 

 doubtless many related beliefs. The combat was con- 

 tinued by Vallisneri, Schwarnrnerdam, and Reaumur, who 

 succeeded in banishing the notion of spontaneous gener- 

 ation from the scientific minds of their day. Indeed, as 

 regards such complex organisms as those 'which formed 

 the subject of their researches, the notion was banished 

 forever. 



But the discovery and improvement of the microscope, 

 though giving a death-blow to much that had been pre- 



