126 DIVERSIONS OF A NATURALIST 



" Pseudodoxia Epidemica, or an Enquiry into Vulgar 

 and Common Errors." The account of the creation given 

 by the poet Milton was based upon the belief in the 

 daily occurrence of such spontaneous generation of living 

 things of high complexity of structure and large size, 

 from slime and mud. The process of creation of living 

 things conceived by him was but a general and initial 

 exhibition of an activity of earth and sea which in 

 his belief was still in daily operation in remote and 

 undisturbed localities. 



In 1668 the Italian naturalist, Redi, demonstrated 

 that putrefying flesh does not " spontaneously breed " 

 maggots. He showed that if a piece of flesh is 

 protected by a wire network cover from the access 

 of flies, no maggots appear in it, and that the flies 

 attracted by the smell of the meat lay their eggs on the 

 wire network, unable to reach the meat, whilst if the 

 wire cover is removed they lay their eggs on the meat, 

 and from them the maggots are hatched. It took 

 a long time for this demonstration by Redi to affect 

 popular belief, and there are still country folk who 

 believe in the spontaneous generation of maggots.^ 



But few, if any, persons of ordinary intelligence or 

 education now believe that these sudden productions of 

 living things, without regular and known parentage, take 

 place. The spontaneous generation of large, tangible 

 creatures having ceased to be an article of general belief, 

 the conviction nevertheless persisted for some time that 

 at any rate minute microscopic living things were 

 generated without parentage. This theory was more 

 difficult to test on account of the need for employing 



1 See the chapter, " Primitive Beliefs about Fatherless Progeny,'' 

 in "Science from an Easy Chair," Second ijeries. 



