134 
Bulletin Wisconsin Natural History Society. [Vol. 10, Nos. 3-4. 
Flight Movements of the Individual .—Three or four of the 
troopers spent a little time after mess the same night in studying 
the flight movements of this midge. We saw that this fly has the 
power of flying backward as well as forward; that is, that there 
is a complete reversal of motion without turning the body around, 
so that it can dart backward rear-end first at nearly the same high 
speed that it can fly forward. Usually in the main swarms, the 
course of the individual flight was that of a pretty fair oval in a 
/-A ' 
plane always perpendicular to the ground. But some of those 
darting rearwards for whatever reason, could take a backward 
flight in almost a straight line. Wheeler (1899, 373) notes what 
are probably other species ‘'often seen on summer evenings moving 
up and down for hours over the same spot. If the observer stand 
with such a swarm between himself and the setting sun he will 
see the tiny flies orient themselves to every passing breeze.” This 
was not uniformly true of C. plumosus, since something like 5% 
of the flies were interweaving flights throughout the swarm, in' a 
manner to break up the fair uniformity of body direction or orien¬ 
tation. 
Westwood (1840, (506), probably referring to midges, as he 
says, “Nemocera of the smaller size”) seems to have been the first 
to mention this body orientation and relegates his observation to a 
footnote, whether to make it the more conspicuous or to hide it 
for fear of inaccuracy, others must decide,—saying, “I have ob¬ 
served that in these dances the insects always fly with their heads 
toward the quarter from which the wind blows.” Ainslee (1907, 
28) notes the same habit in a Tipulid and generalizes for all weak¬ 
winged flies. He describes the individual Tipulid’s flight as in 
three movements, repeated continually, viz.: a slow curving rise 
for 2.5-3.5 dm. (10 or 15 inches), a rapid perpendicular fall, and 
a peculiar swaying flight that affected the exact position of the 
