92 
of March, or even the Cth of April. It we may 
be allowed to make any comparison with the first 
cletch from the eg'g', which infest the Apple, there 
we find a period of near a month betwixt those 
leaving the egg and the second cletch being vivip- 
arously established, and this before the parent 
has attained half its growth. If we make an 
allowance for the deficiency in size of those on 
the Apples, and the period in which those on 
Peaches ai'e stated to exist, we may, upon an 
average, (allowing there to be eggs) suppose 
those on Peach trees to be excluded from the egg 
in January, a period very unlikely for those little 
animals to be brought into existence, as there is 
then neither food nor warmth to keep them alive. 
Several generations are produced in the course 
of the spring months, the last of which appears 
to take flight about the middle or latter end of 
June. It is remarkable that the trees, from the 
said period to the month of September, should 
remain quite free, (or at least I never found it 
otherwise), and then again be visited by the same 
species in its winged or perfect state. 
Those emigrants shortly after popxdate their 
new residence, and, when the parental office is 
accomplished, die. Their offspring feeds till, re- 
pulsed by cold and the deprivation of food, they 
are compelled to retreat for the winter months ; 
but the returning spring stimulates or incites 
them to resume their attack, and prolifically es- 
tablish their progeny, as before-mentioned in tlie 
