234 Trans. Acad. Sci. of St. Louis 
not successfully come closer) something might happen 
beyond one’s sense of sight. 
These adults are flower-loving insects. On August 13, 
two specimens were seen on flowers in a field some dis- 
tance away. It may well be that this would account for 
the reduced numbers during the morning hours, while at 
noon they were present in full force; perhaps they were 
out in the blossoms satisfying their morning hunger, or 
again perhaps they had gone out into the vegetation to 
spend the night (their sleeping habits have not yet been 
ascertained) and were slow in returning to the day’s 
activity. With the cold nights of early September they 
began noticeably to wane, and none were seen alive after 
September 12. 
These flies were seen throughout the season in vary- 
ing abundance. It seemed at first that with their play- 
ing and dancing about the bank they were merely mark- 
ing time, but, since they continued it all summer, it ap- 
pears that they are the kind of beings that can seemingly 
dance and frolic through life and yet make a success of 
living. Some were seen in copulo on July 26, 1922. 
One pair remained in copulo, back to back, for a half 
hour, resting on a shady portion of the bank. 
In 1918, this fly was no exception in the phenomenot 
of all life appearing a month earlier. A few individuals 
were seen out on July 17, 1918, as against ‘August 1, 
1917. Until the end of July they were very abundant, 
and like their ancestors of yesteryear, they kept busy 
most of the time, doing nothing in particular, unless 
they oviposited on the sly. The shedding-skins as well 
as the flies gave evidence of an increase in population. 
This increase was probably at the expense of the dwellers 
in the wood-tunnels above, for as I have already show? 
