91 
emigrating from other trees or plants. It is cer- 
tain that when the trees are infested at so early 
a period as already mentioned, they are not pro- 
duced from an egg, as some authors assert ; nei- 
ther, as some erroneously believe, ai’e they brought 
by the east wind. They are viviparously deposited 
by the imperfect or immature parent, which has 
survived the winter in the earth, or in crevices of 
trees, walls, &c. and which was impregnated pre- 
viously to its x’etirement, for I find, in my memo- 
randum for 1825, that the latter end of March, 
and beginning of April, was fine, warm, and 
sunny weather, which appears to have animated 
the Aphis to ascend the tree, where I found 
several large full grown ones on the 6th of April, 
upon the bloom and leaf buds, which were just 
biu-sting through their external cuticle or skin, 
from which they derived their support, and where 
they were surrounded with a numerous progeny ; 
and although the progenitors at the first were 
but few, yet, from their incredible increase they 
would apparently soon have populated the trees. 
In a memorandum made March 10th, 1826, it 
appears that I found full grown Aphides on 
the bloom which was at that time quite green, 
with the exception, perhaps, of one in five 
hundred, which showed a little pink. It must 
be allowed, that were the first occupants pro- 
duced from an egg, they could not have attain- 
ed to their full growth, and, indeed, appar- 
ently to a size larger than common, by the 10th 
G 2 
