1944] How OcLynerus Suspends Her Egg 3 
1923) that Fabre laid too much stress on the correlation of the 
well-known liveliness of Eumenid’s caterpillars and the alleged 
delicacy of the Eumenid egg. 
It is a matter of common observation that the Eumenid prey is 
seldom stung to death. On opening a nest of Eumenes or Odv- 
nerus practically all of the caterpillars respond to stimulation 
and many move spontaneously. It is not at all a rare occurrence 
that a caterpillar begins to crawl as soon as set free. One of the 
scenes in our motion pictures of Eumenes is that of a merry 
scramble of four or five surviving caterpillars with two large 
wasp grubs holding on — for this case concerned an exceptional 
nest in which two eggs had been laid. 
Fabre considered the egg much too delicate to stand the jostling 
of such vivacious prey entombed alive; he states that he was 
never able to rear grubs from eggs that were disturbed or removed 
from their original sites. But not so Ferton, who seldom failed 
under similar circumstances. Indeed, he once dropped an egg 
with the lively canker worms into a bottle, carried the specimens 
some miles on horseback, yet reared a wasp from the egg. We 
have also reared wasps from eggs that had been carried about in 
the jug nests of Eumenes or in bamboo tubes stored by Odynerus, 
although these were not handled with any special reference to the 
force of gravity. 
Ferton points out, furthermore, that the cells are usually so 
tightly packed with caterpillars that the egg must needs be 
pressed against the wall and not able to dangle freely at all. This 
can readily be corroborated by opening almost any fully stored 
cell. If one split a bamboo tube full of caterpillars, it will be seen 
that the masses of worms literally swell up as the retaining wall is 
removed. 
To these points we are able to add our direct observation on 
what happens to the egg as viewed through the wall of the glass 
tube while the insect is at work. 
After the egg has been suspended in the depth of the cell, forag- 
ing begins. As the caterpillars are brought in they are stuffed 
with might and main into a closely fitting firm mass at the bottom 
of the cell. This happens also in smooth- walled glass tubes in 
which the worker finds only a precarious footing. The egg is al- 
ways pushed around and often squeezed against the glass or be- 
tween caterpillars, which are thus thoroughly immobilized by 
virtue of mutual pressure. 
Ferton is of the opinion that the chief value of the suspensory 
