226 EARLY STUDIES IN COMPARATIVE ANATOMY 



no ill eflFects were observed. Only when fresh venom 

 was applied to wounds did death ever follow. Redi, 

 who no doubt made the experiments, went on to 

 examine the poison-gland and poison-tooth of the viper. 

 He seems to have concluded that the tooth was only 

 channelled, instead of being perforated by the poison- 

 duct, as it really is. 



The Generation of Insects ^ 



This treatise is historically important because it 

 dispelled ancient superstitions by direct experiments. 

 It is a pity that Redi's decisive proofs, which might 

 have been related very concisely, should be loaded with 

 two hundred pages of discussion. The question to be 

 settled was whether, as Aristotle had taught, insects 

 could be generated spontaneously by putrefaction. Eedi 

 proved experimentally that the flesh of the same animal 

 might yield more than one kind of fly, while the same 

 fly might be hatched from diff'erent kinds of flesh. He 

 saw the flies laying their eggs in flesh, and dissected 

 eggs out of their ovaries. The larvae and pupae of 

 common flesh-haunting flies were noted and compared. 

 It was thus proved that the generation of a particular 

 maggot or fly in flesh did not depend upon the kind 

 of flesh, but on the kind of fly which had got access 

 to it. Flesh was placed in bottles, some of which were 

 left open, while others were closed with paper or gauze. 

 The open bottles produced larvae, pupae and flies, while 

 the closed bottles produced none, though flies, attracted 

 by the odour, strove to enter, and in some cases laid 

 their eggs on the gauze. 



Among the baseless fables handed down from ancient 

 authors was the Bugonia fable, well-known to readers of 



1 Esp. intorno alia generazione degV Insetti. 



