[ *85 ] 
I'uch different appearances, and almoff induced- to 
give credit to the old dodirine of equivocal gene- 
ration. That fhe fame kind of animal fhould, at 
one time of the year be viviparous, and at another 
oviparous, was an opinion I could then by no means 
entertain. This, however, frequent obfervation has 
at laft convinced me to be fadt j having found thofe 
Aphides, which appear early in the fpring, to pro- 
ceed from fmall black oval eggs, which were de- 
pouted on the lafl: year’s (hoots in autumn : though, 
when it happens that thofe infedls make too early 
an appearance, I have obferved the greateft part 
to fuffer from the (harp weather that ufually lucceeds; 
by which means the rofe trees are fome years in 
a manner freed from them. 
Thofe which wichftand the feverity of the wea- 
ther, feldom come to their full growth before the 
month of April ; at which time they ufually begin 
to breed, after twice cafting off their exuvire, or out- 
ward-covering. It then appears that they are all 
females, which produce each of them a very nume- 
rous progeny, and that without having intercourfe 
with any male infedt. As I obferved before, they 
are viviparous ; and what is equally uncommon, the 
young ones all come into the world backwards. 
When they fird: come from the parent, they are en- 
veloped by a thin membrane, having in this (itua- 
tion the appearnce of an oval egg j which I appre- 
hend muff have induced Reaumur to fufpeft that 
the eggs difcovered by Bennet were norhing more 
than abortions. This egg-like appearance adheres 
by one extremity to the mother, while the young 
©ne therein contained extends the other j by that 
V ol.LXI. B b means 
