252 Mr. F. WalkeFs Descriptions 0 / Aphides. 
an organ of the same system sending inwards and inclined a little 
down a similar tube. The summit of the nectary is contracted 
and then expanded again in a sort of lip, thus acting as a sphinc- 
ter.” The legs are pale green, long and slender ; the fore-thighs 
are stout, and each has a small obtuse tooth on the inner side of 
its tip ; the knees, the feet, and the tips of the shanks are brown ; 
the shanks are hairy, longer and more slender than the thighs ; 
the feet have two joints ; the first is very short, the second is 
linger and furnished with claws : the wings are colourless and 
much longer than the body ; the wing-ribs and the wing-brands 
are green ; the veins are brown, and their tips are slightly clouded : 
the fore-wing has a strong rib-vein running parallel to and a little 
below its fore-border ; four branch-veins spring from it ; the first 
and the second pass to the hind-border of the wing ; the third is 
divided at about one-third of its length ; one branch joins the hind 
border, the other is again forked, and the upper part of the fork 
runs to the tip of the wing ; the fourth or radial vein is short and 
curves upwards : the lower wing has a rib-vein that runs very 
near the fore-border, and sends forth two simple veins to the 
hind-border. 
1st variety. The lobes of the middle chest and the disc of the 
breast are black. 2nd var. With a row of transverse black spots 
along the back of the abdomen : the legs are pale yellow ; the 
knees, the feet, and the tips of the shanks are black : the wing- 
ribs and the rib-veins are yellow. 3rd var. The disc of the head, 
two spots on the fore-chest, and the middle chest are black : the 
feelers are black and covered with a white bloom ; their base is 
dull yellow. 4th var. The body is tinged with bright red. In 
the 5th var. the disc of the head and the middle chest are green, 
in the 6th they are buff, in the 7th they are red, in the 8th they 
are lilac. 9th var. The body is deep black ; the head is tawny. 
10th var. The whole body is covered with a white bloom. 11th 
var. The body is pale red, or rust-colour : the back of the abdo- 
men is traversed by a row of short black bands : this variety 
occurs chiefly in the autumn. 12th var. The wing-brand is 
colourless. 
Sometimes one hundred of these insects may be seen under a 
single leaf, and innumerable swarms hover about the sycamore- 
trees during the fine calm autumn evenings. In this season it 
still continues to bring forth young ones, which the fall of the 
leaf soon carries away to the earth, where they perish. When 
it abounds, a great variety of insects, especially of Hymenopterous 
and of Dipterous flies, come to feed on its honey-dew ; this matter 
stops the pores and hastens the decay of the leaf, which towards 
the end of autumn is often covered with little Acari, the devourers 
of the dead Aphides. This honey falling on the upper surface of 
