142 
Bulletin Wisconsin Natural History Society. [Vol. 10, Nos. 3-4. 
skin of the thorax parts, the head and shoulders of the gnat appear 
and it comes forth steadily as though some one were squeezing it 
out. In fifteen seconds it is free, and flies away!” 
Adult, Vitality. Annual Occurence or Oftener ?—On the 
way, it was discovered that unlike some flies, the midges caught 
the previous night were still living although in tight vials, thus 
showing their ability to get along on little air. They were killed 
seventeen hours after the time of capture by chloroform. In con¬ 
trast to this vitality, note their short lease of adult life, suggest¬ 
ing Mayflies: In the afternoon, as only one midge was seen near 
the baseball grounds, a ramble nearly a mile northeastward 
towards the lake shore of Lake Winnebago disclosed the fact that 
many more midges were near the lake in this section, just as had 
been observed at Neenah. Moreover some were dead in the 
fields, butf one day later, Aug. 17. Dead ones were seen on and 
about stumps in the pastures, and many others seemed to be 
hardly able to move or were feebly kicking on their backs. No 
apparent cause for this could be found except that their natural 
life was spent by the time the necessary mating* swarm was over. 
Both males and females were among the dead, but the males 
seemed to be twice as abundant as the females. Thus we may 
explain the few females seen in the night swarms by the deduc¬ 
tion from observations that more males were produced than 
females. Stumps, fences, and other weather-worn wood masses 
were all specked up with the green midge voidings, just as men¬ 
tioned for the calvary tents the day before. 
As dusk deepened this same afternoon, Aug. 17, the midge 
dance went on with hardly abated resonance. From the number 
of dead and sluggish midges seen in the fields in the earlier after¬ 
noon, I judge that the maximum of the swarm period had been 
reached the previous night and that this evening of the 17th must 
have commenced the beginning of the decline in abundance. 
Aug. 18th, 1910. the cavalry trip took us towards Fond du Lac 
where the presence of midges became almost unnoticeable, despite 
the fact that we were approaching a favorable breeding ground, 
the south shore swamp. Thus the swamp could hardly be consid¬ 
ered the center of their present breeding grounds. Aug. 19th, 
the troop passed beyond the lake margin. Thence midges were 
