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 hacks of the others for an hour or so ; 

 then, as if having made up their minds, they toddle up- 

 wards, walking on the hacks 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 by the remainder of the body, 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 be the slowest part of the process. The manner in which the parent 

 rid herself of the new-born 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 and the antennae, were thus gradually withdrawn, but I could not detect any 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, ft 



