126 QUINCE CULTURE. 
side, black nectaries an1 tail appendage. The neck is 
green, the body is yellowish green, striped often with 
a deeper green. The young are almost white. The 
wings are transparent, with dark veins. 
When they become gorged with sap, the excess is 
thrown out through two little tubes, which project, one 
on each side, from the anterior part of the body. These 
are their nectaries, through which they eject a honeyed 
fluid known as honey dew. ‘To feed on this, a variety of 
ants and flies will be found to visit them. The ants, 
with whom they live on friendly terms, stroke the 
aphides with their antennze to induce them sooner to 
void this sweet liquid, which they hastily devour. 
Experiment has shown them capable of producing 
eleven generations in seven months, when frost closed the 
opportunity. In a heated room they continued to repro- 
duce a constant succession, without the intervention of 
males, for four years. Even then there was nothing to 
show why it might not have been continued still longer. 
Dr. Burnett considers this anomalous mode of increase 
as a process of budding, and that the whole series, like 
the leaves of a tree, constitute only one generation, 
resulting from the previous union of the sexes. Réaumur 
proved one capable of increasing to six thousand millions 
in five generations. The leaves of trees infested with 
aphides soon become distorted, or curled back so as to have 
their tips touch the twig whence they sprung, thus pro- 
tecting them from the sun and rain. 
Remedies.—The eggs can be destroyed by a wash of 
caustic lime or soda. The young may be destroyed by 
alkaline solutions, and by tobacco water, made by boiling 
a pound of stems in a gallon of water. ‘Twigs can be 
bent into it with but little waste of the solution. Small 
birds in winter hunt over the trees for its eggs, and in 
summer for the lice. The Jchnewmon fly deposits her 
egg in the aphis, and this soon produces a destroyer, 
