76 GENERATION OF INSECTS 



or in the contrary case, left in an exposed place, will pro- 

 duce various insects of different species, according to the 

 animals that have made deposits therein. But I have 

 noticed that a preference is sometimes shown for a 

 special vegetable or fruit in selecting the nesting-place. I 

 had seen many flies light on a melon that showed later 

 small worms, which, after four days, changed into eggs 

 [pupse] from which in four more days there were born 

 an equal number of gnats. 



In some pieces of mashed melon on which gnats and 

 common flies had been feeding, together with another 

 kind of fly, small, black, and with long antennae, there 

 were dropped worms of different size, that in due time 

 were changed into eggs [pupse] of different size. Com- 

 mon flies came out of the larger ones in eight days; 

 from some of the smaller ones gnats appeared after four 

 days, and from those of medium size were hatched the 

 largest flies of all. I had the same result in experiment- 

 ing with cucumbers, strawberries, pears, apples, plums, 

 lemons, figs and peaches. 



In my experiments with raw and cooked pumpkin, the 

 common fly was the only insect that hatched. But I 

 must not neglect to mention that all worms hatched in 

 a certain preparation of boiled pumpkin and egg, which 

 had reached the state of decomposition, acted in an ex- 

 traordinary manner, rolling themselves about in the pap 

 that stuck fast and covered them up, so that they re- 

 sembled little clods of earth from which finally the flies 

 were hatched. Now, anyone who did not know that an 

 egg was concealed in each ball would have reasonably 

 judged that those flies were hatched directly from the 

 little balls. From some such illusion, I believe, originated 

 the error of Pliny and others, who relate that infinite 



