C 199 ) 
black Flies, and the Caterpillars which foon follow them, 
we ftiould find that the Caterpillars generated by black 
Flies, change to black Flies again. 
About two Years fince I put fome Cheefe-Maggots 
in a Glafs Tube in my Pocket, and at laft found the 
Maggot turned to a red Aurelta from pure white; and 
thefe again changed into a black Fly ; which Experiment 
I ofc renewed with the fame fuccefi, though I could not 
keep thefe Flies till they laid Eggs, it may be for want 
of convenient Food. 
From thefe and feveral other Obfervations, I conclude 
there is no Generation but from the Parent Aaimal. 
Hh z 
