60 Bulletin Wisconsin Natural History Society [Vol. 11, Nos. 1-2 
electric fan outdoors so as to make a gentle air current, and with 
an electric heater warmer air could be manufactured and by 
boiling water on same, increased humidity could be provided. In 
the absence of experimental proof, I wish to refer to Radius 
notes above quoted that midges orient even to “grey stones, foot- 
paths, or white paper,” and compare my later data. 
May 29, 1912, north of the University Dairy building, midge 
swarms occurred in the flat below the hill on which the Dairy 
stands and below the tops of the trees bordering Lake Mendota, 
to the north of the flat. The midges of a medium-sized species 
appeared to be oriented to no trees, and hovered above cane 
fruits, but not oriented to any particular clump of canes or fence 
posts supporting the canes. Not 50 per cent of the midges stayed 
oriented to the light wind which was variable. This swarm 
showed more irregularity than others noted. 
On June 3, the afternoon north wind abated so that by 7 p.m., 
a swarm of tiny midges were flying above the Lower Campus. 
Although this is bare ground (used for baseball) no particular point 
on the ground seemed distinguishable. Professor Sanders and I 
walked through the swarm once or twice and waved at it without 
any reaction as definite as described by Schuster (1904, November. 
Massenschwarm der Federmiicke Chironomus plumosus). Der 
Zool. Garten, v. 45, no. 11, pp. 344-5) and quoted in my previous 
paper on C. plumosus (Bull. Wis. Nat. Hist. Soc., v. 10, nos. 3-4 
December, 1912, p. 131) as bouncing instantly upward out of 
reach. In Morley’s paper (1. c.), few of the dozen observers there 
noted paid attention to swarm location, save that one was over 
Ascot Heath, some other swarms were flying over a moat, and 
that others were disturbed by a slightly gusty southwest wind 
so that when the companies of dancing insects were struck, “they 
descended and always rose to the height of invisibility during the 
frequent lulls.” 
To match Radi’s case of a footpath, I give my notes of June 
4, 1912. About 7 p.m., thousands of a small midge (nearly all 
1912 notes are supplemented by specimens deposited at the State 
Entomologist’s office) were swarming along the cement sidewalk 
leading up the south slope to Agricultural Hall, Wisconsin Uni- 
versity. This great swarm followed the exact curve of the cement 
walk continuously for a hundred paces or 18 rods, and was pecu- 
