70 
HOP-FLY. 
commence sap-sucking close to their mother, the spaces 
get filled up, and the old ones look like giants among the 
rest, — as here and there an ox in a flock of sheep — when 
all the spare room is filled up, and the stalk completely 
covered. The young ones, on making their first appearance 
in the world, seem rather posed as to what to be at, and 
stand quietly on the backs of tlie others for an hour or so ; 
then, as if having made up their minds, they toddle up- 
wards, walking on the backs of the whole flock till they 
arrive at the upper end of the shoot, and then settle 
themselves quietly down, as close as possible to the 
outermost of their friends, and then commence sap-suck- 
ing like the rest; the flock by this means extends in 
length every day, and at last the growing shoot is 
overtaken by their multitude, and completely covered 
to the very tip. Towards autumn, however, the blights 
undergo a change in their nature, their feet stick close 
to the rind, their skin opens along the back, and a 
winged blight comes out — the summer generations 
being generally wingless. These are male and female. 
a young Aphis was then protruding from that of the parent, and was quickly 
followed hy the remainder of the hody, the thorax and the legs. When these 
parts had passed, there was a slight cessation of parturient action, the head 
being still retained in the vaginal passage. The disengagement of the head 
seemed, to he the slowest part of the process. The manner in which the parent 
rid herself of the new-horn Aphis was deserving of notice. When the little in- 
sect was almost entirely extruded from her body, it clung with its feet to the 
plant ; while the female Aphis, at short intervals, gradually elevated her body, 
and with a slight jerk seemed to labour to remove it. The young Aphis re- 
peatedly missed its hold, but quickly regained it, and was thus as it were par- 
tially dragged forth. The head, with its small black eyes, parts of the mouth, 
and the antennee, were thus gradually withdrawn, but I could not detect any 
foetal coverings removed with them. The whole process of birth occupied about 
five minutes. Immediately after the young had escaped from the parent, it 
