180 
Psyche 
[September 
attribute it to the work of the larvae. An examination of 
this material under the microscope does not show a struc- 
ture of spun silk ; hence it is probably made of the contents 
of the alimentary tract, which are completely emptied at 
the time of pupation. It is a known fact that in certain 
aculeate Hymenoptera, the excrementary material of the 
larva is retained until pupation time when it is emptied and 
fashioned into a cocoon. Here in the white-banded bee is a 
similar condition, with the slight change of using the mate- 
rial for caulking purposes instead of cocooning. 
That Entechnia taurea attains gregariousness is due just 
as much to the fact that the clay bank is protected as to 
their community instincts. In 1917 I noticed a sickly colony 
in a clay bluff about one-quarter mile south of the bank. 
These burrows went horizontally into the bank at a road, 
and had no protection from the weather. Only three turrets 
and their builders were seen. This colony did not become 
established, and in 1918 no progeny were there. In 1918, 
two turrets were found at the side of a foot-path on a hill- 
top in the shade of an old oak. In the same season, the 
dirt about the base of an uprooted tree at a point about 
fifteen miles distant from the bank had twelve turrets of 
this species. The knotty roots served as protection from 
the weather, so the colony there was able to grow. The 
fact that the bees of the Wickes clay bank became colonized 
under the protection of the porch is no mere accident, but 
the following notes made at various distant localities, show 
that the habit of seeking protected places is general for this 
species, or, to put the explanation in other words, those 
bees which nest in sheltered areas grow into colonies and 
those which do not, either they or their progeny fall vic- 
tim to the elements, landslides, etc. 
At Keys Summit, Mo., a clay embankment by the road- 
side and facing the western sun, had forty or fifty of these 
turret-topped nests, penetrating the slope horizontally, 
scattered along the slope for about a hundred and fifty 
yards. This bank was about ten feet high, and some vegeta- 
tion and a few trees were growing there whose roots held 
the earth firm and made protecting niches in the bank. All 
of these nests were found in the protected spots, and none 
