1922] Uichanco — Notes on Parthenogenetic Macrosiphum 77 
claimed, since the latter membrane arises as a secretion of the 
egg-periplasm, and has no direct relation to the follicular epithe- 
lium. 
The extrusion of the nymph from the vagina, from the time 
the caudal portion of the abdomen of the former begins to pro- 
trude until the entire body is exposed, takes about five or ten 
minutes. The insect remains in the condition described above) 
attached by the anterior margin of the head and the bases of the 
antennae to the external opening of the mother’s vagina for 
about ten or fifteen minutes. At the end of this time, the young 
insect has dried its skin well enough to set the appendages free 
from their attachment to the body. A waving motion of the 
antennae and of the legs then ensue; but the nymph does not 
seem to struggle to make its final escape. After about five more 
minutes, the chitinous exoskeleton has probably hardened 
sufficiently, and the mother then executes two or three sudden 
peristaltic movements of the abdomen, which set the young 
nymph free. The newly born aphid usually remains in close 
proximity to the place where it is deposited by the mother. In 
about fifteen or twenty minutes after birth the nymph begins 
feeding, and by this time also the characteristic colors of the 
body and appendages become evident. 
The position of the mother during parturition is the same as 
that described in connection with her feeding habits. The 
abdomen is situated uppermost and the head directed toward 
the ground. In fact, parturition goes on simultaneously with 
feeding, apparently without in the least interfering with the 
latter process. 
Summary of Section V. 1. At birth, the young makes its 
appearance with the caudal portion of the body first. 
2. After extrusion from the vagina, the nymph remains 
attached by the anterior margin of its head to the vaginal slit of 
the mother until the exoskeleton of the young hardens. The 
process requires about ten to fifteen minutes, when the nymph 
finally becomes separated from the mother. 
