12 
feeding-, as though they were told th-at the one is a 
more sure foundation than the other, and that if 
they did not quit their old habitation it would not 
afford protection to their prog-eny, which with it 
must be brought to the ground and perish. The 
eggs are completely black, of an oval shape, and 
may be pretty well discerned by the naked eye. 
The larvae when first produced are of a dark green, 
with a black head and legs. The male and female 
in their perfect state are furnished with fine erect 
wings, nearly three times the length of their body, 
which assist them to emigrate into different parts. 
The last emigration takes place in September, the 
emago or perfect insect, survives a few weeks to 
establish her progeny, and then immediately dies. 
It is supposed, generally, that the Aphides are 
brought into this country in the beginning of 
spring months, by the east winds ; but this is quite 
erroneous, as evidently appears from the circum- 
stance that those which make their appearance 
first are not in their perfect state. The wind must 
be strong indeed to bring them from any distance 
when they are not furnished with wings. It is ti-ue 
that through the course of the summer and autumn 
months, at the time of emigration, the perfect in- 
sects are taken to greater or lesser distances, ac- 
cording to the power of the wind ; but those which 
ai'e seen so early in the spring upon the apple tree, 
are produced from eggs. Other species that were 
in existence in the autumn months will also be 
found on their favourite plants, and, after lying 
