Mr. Newrort on the Generation of Aphides. 283 
surprised to find that these specimens were again producing living young. 
One of the large apterous females had already produced its living offspring, 
and the other was at that very moment in the act of parturition. The poste- 
rior part of the body of 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 insect was almost entirely extruded from her body, 
it clung with its feet to the plant; while the female Aphis, at short inter- 
vals, gradually elevated her body, and with a slight jerk seemed to labour to 
remove it. The young Aphis repeatedly missed its hold, but quickly regained 
it, and was thus as it were partially dragged forth. The head, with its small 
black eyes, parts of the mouth, and the antennz, were thus gradually with- 
drawn, 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 turned about on the leaf and moved 
very slowly, while the female plunged her proboscis into the plant to take 
food after her exertion. 
These brief observations confirm the statements of former naturalists, that 
the Aphides deposit at one period true ova, and at others produce living 
young; and they lead us hereafter to inquire more particularly respecting 
the circumstances which accelerate the one, or retard the other form of 
development. 
VOL. XX. 9 P 
