14 MAN, — THE ANIMAL 



belief that a horse hair placed in water may be- 

 come a living worm, as well as other similar 

 crude notions about the origin of living things. 

 This idea that life could come from non-living 

 matter was first successfully questioned by Redi, 

 1680, who proved that maggots would not grow in 

 meat if the flies were prevented from laying their 

 eggs on the meat. Huxley says of Redi, "The 

 extreme simplicity of his experiments, and the. 

 clearness of his arguments, gained for his views 

 and for their consequences almost universal accept- 

 ance." 



Seven years after the experiments of Redi, 

 microscopic animals and plants were discovered 

 and the theory of spontaneous generation took on 

 a new lease of life, as It was used now as explana- 

 tion for these minute forms of life. The Italian, 

 Spallanzani, 1777, the Frenchman, Pasteur, 1864, 

 and the Englishman, Tyndall, 1876, are the three 

 great men who successfully devised experiments 

 that conclusively demonstrated that microorga- 

 nisms did not arise spontaneously. 



From the time that Tyndall published his 

 studies until to-day, there has been a very general 

 agreement among biologists that living things 

 arise from some form of existing life and not from 

 Inanimate nature from time to time as the ancients 

 believed. The critical observations of the past 

 forty years have conclusively sustained this gen- 



