400 Trans. Acad. Sci. of St. Louis 
At the examination on March 30 the lower four or- 
ganisms were typical quiescent larvae, all very much 
alike, while the two upper ones were perfect pupae, with 
wing-pads becoming slightly brown, and the eyes pig- 
mented. Just two weeks later, April 12, it was found that 
two of the four lower ones had changed to pupae; they 
were not the first and second, however, but the second 
and fourth from the bottom, leaving the first and third 
still larvae, the first in the earlier stage. On April 15 
the conditions were still the same, the first and third still 
larvae. By May, the third had pupated; the fifth and 
sixth were entirely black. By the middle of May the two 
uppermost had emerged; the third from the bottom, the 
unfortunate laggard, was dead in the twig; the bottom 
one had at last become a black pupa. The wasps in emerg- 
ing had demolished the roofs above their heads. The 
last finally emerged on May 31. Thus the entire family 
developed and emerged in sequence from top to bottom, 
excepting that the third lagged in its development until 
its death. 
Another twig contained a nest in all essentials similar 
to that described above. It was accidentally placed up- 
sidedown in its jar. When the young wasps emerged 
they bit a dise out of the mud next to their heads, making 
a round hole in the partition through which they emerged, 
head downward. This certainly indicates, contrary to 
Fabre’s suggestion, that the force of gravity has nothing 
to do in guiding their emergence.* 
Stenodynerus zendaloides Robt. [S. A. Rohwer]. 
Unlike other wasps, this species uses both pith and mud 
in nest-building. The mud helps the cocoonless wasp to 
survive, in that it is worked up into a sort of cocoon 
*For additional facts on the life histo of this species see our 
“Wasp Studies Afield,” 334-340, 1918. = . 
