( 18-1 ) 



many people think they are brought to us by the North wind, or 

 even bred in the clouds : but fuch men I leave in their error. 



Thefe black Flics (and clpecially thole which I had fuppoled to be 

 impregnated) being confined in two glall'cs, laid a great number of 

 eggs, very long in proportion to their thicknefs ; whence I gathered 

 that they would be changed into very long and flender Maggots or 

 Caterpillars. But as all the FUes foon afterwards died, and not one 

 of the eggs produced u living creature, I confidered that perhaps 

 thefe Flies might die for want of food, and that the eggs might be 

 .aid before their time, having often obferved flies and moths when 

 I happened to handle them fo roughly, that they afterwards died, 

 immediately after fuch handling, to empty themfelves of all the 

 eggs they contained. 



I did intend here to defift from publiflfmg any thing farther re- 

 fpe6ling the propagation of thefe infedls, deeming that I had proved 

 fufliciently, that all living creatures were produced by the ordinary 

 courfe of generation ; but my friends in different parts of the world, 

 exhorted me to proceed in my difquifitions on this fubjc<ft, as being 

 w^hat many learned men defire may be profecuted. 



To proceed then in my examination of this fubjeft. In the 

 month of May, in the following year, the weather being warm, 

 and my fruit trees in blollbm, I fought for fome of the flying in^ 

 fedls I have mentioned, and prefently faw many of them coupling 

 together. But though they were nimble in their motions, and well 

 fitted to fly, and moreover had fix feet, and on each foot two 

 claws, yet on my fliaking the leaves or branches ever Jo littlQ, 

 they gathered up their feet and fell to the ground ; feveral of thefe 

 fmall animals I brought to my ftudy in a glafs, to make my obfer- 

 vations on them. 



1 found the wings of thefe creatures to be about twice the length 

 of their bodies : but, if we confider that thofe wings are covered 

 with thoufands of hairs, and obferve, that when the wing is fpread, 

 not t)ie Jeall fold or joint can bedifcovcred in it, though it Iks 9n 



