Field Studies of the Non-Social Wasps 397 
substance; this evidently was also cocooning material 
thrown out in clearing the alimentary tract for pupation, 
but without any attempt to utilize it for a cocoon. 
By April 12 all seemed equally well developed except- 
ing in the pigmentation of the eyes; in this detail, one 
could see a regular gradation of color from light brown 
to black, appearing in a continuous series from the bot- 
tom upward, or inversely to the order in which the eggs 
had been deposited; that is, the last egg deposited 
showed the most advanced degree of development. Two 
days later the lowermost two were still creamy white 
pup with the eyes highly pigmented; the third was black 
with the legs still white; the fourth, strange to say, was 
a little lighter ; the fifth likewise was in a transition stage 
of pigmentation, but darker, while the sixth was entirely 
black, with only spots on the lower abdomen where close 
Scrutiny revealed that the pigment was still thin. By 
‘April 30 all were fully pigmented and mature, and only 
the bottom one had the legs still adhering to the sides 
of the body. The fourth, which at the last examination 
had vexed us because it broke our pretty sequence, was 
now dead; its slowness in developing was probably due 
to a diseased condition of the larva, and not to a break 
in the laws of inverse priority. 
On May 11, I discovered that all were dead excepting 
the lowermost one, which virtually was hopelessly im- 
prisoned beneath the long tier of unopened cells. In cells 
2 and 3 the partitions above were bitten and perforated, 
which shows that these wasps had attempted to emerge 
normally, but had found the way above them blocked. 
The lack of moisture may well be a factor causing hard- 
ship in their emergence in abnormal surroundings; in 
the open fields the twigs are normally exposed to an 
abundance of moisture at that time of year. 
