The Ecology of a Sheltered Clay Bank 173 
tact (Fig. 11), and all three species varnish the interior 
with the waterproof substance already referred to. 
As noted above, they customarily work from early 
till late. On June 17, 1918, when the temperature* 
dropped from 98 degrees to 79 degrees Fahrenheit, their 
activities were greatly lessened. Less than a dozen as- 
sumed activity at all. 
I tried to find where they got their pollen. On a per- 
simmon tree some two hundred yards away, with its 
blossoms already deteriorating I found many bees, in- 
cluding this species, getting nectar. The two popula- 
tions, bees and blossoms, waned at the same time. In 
1921, notes on the relation of this species to the persim- 
mon blossoms were made, and details are given else- 
where. What other sources of food supply they may 
have had I did not learn. 
From May 28 to June 13 of the year 1920, they had 
built turrets to the enormous number of 675, a substan- 
tial increase over the number for the previous year. On 
July 21, only a week later, these short lived creatures 
were almost gone; only two live females could be found, 
the remnant of the recently noisy and mighty throng, 
and dead specimens of A. abrupta were scattered all 
about. In 1921, Man was again a factor in regulating 
the abundance of Anthophora life; the tenants of the 
“‘Ham and Bud’? club-house unwittingly caused the death 
of hundreds of these little creatures, by merely going 
away and leaving the door of the screened porch open. 
The bees, in their circuitous flights, entered this open 
door at the head of the stairway (Fig. 8, point x), and 
Were not able to find it again to make their way out; thus 
the screening which was intended to keep insects out, 
ee 
*U. S. Meteorological Summary for June, 1918. 
