136 
Bulletin Wisconsin Natural History Society. [Vol. 10, Nos. 3-4. 
out-door conditions, the mother fly attaches the egg-rope to some 
object close to the waters edge (Higginson 1867, 176; Howard 
1908, hi), the eggs not being arranged as in the Culicidce 
(Westwood 1840, 515), and at once the egg-rope (Miall 1903, 
146-7) swells ‘‘into an abundant transparent mucilage making the 
eggs so slippery that birds or insects can not grasp them; it also 
spaces the eggs, and enables each to get its fair share of air and 
sunlight.” It must also be antiseptic as it “prevents water-molds 
from attacking the eggs. Long after the eggs have hatched out, 
the transparent envelope remains unchanged,” having been found 
nearly an inch long “on the edges of a stone fountain in a garden, 
or in a water-trough by the side of the road.” As to dimensions 
(Higginson 1867, 176) says the egg-rope is “cylindrical in form, 
not exceeding three-fourths inches in length and one-eighth inch 
in diameter, one end free,” containing over 200 eggs. As to the 
time of year, Kofoid (1908, 286-7) found in the Illinois River, 
1894-9, fragments of the egg-string of unidentified species “in all 
months but February and December, though twenty of the thirty 
records and 81% of the individuals appeared in May-August. 
The numbers are never very large, the maximum record, 5,424 
per cubic meter (of water-tested) on June 29, 1894, being due to 
a number of fragments of egg-strings.” 
Breeding Grounds .—Without further opportunity to investi¬ 
gate at the time of observation, one would feel justified in saying 
that the midge swarms originated in and around Lake Winne¬ 
bago, that they do not fly many rods from the point of emer¬ 
gence ; as witness the less numbers at the Neenah store windows 
and no evidence of swarms over house yards or streets in town, 
( Fedtschenko, 1891, 181, notes their localised distribution)—that 
they find food enough in the “bloom” hereinafter noted, and other 
abundant organic matter, and have, we may suppose, something 
to do with the excellent fish supply of Lake Winnebago. Many 
of these matters need experimental proof and this preliminary 
paper, after noting such lacunae, will best confine itself to further 
facts. Lake Winnebago is a shallow lake “28 miles long by 10 or 
12 broad in its greatest width” (Marsh 1903, 2 and 3) and “it is 
probable that it is nowhere over about 25 feet in depth. It is evi¬ 
dent to a superficial observer that the plant life during the sum¬ 
mer is very large, and it has been assumed that the abundant pro- 
