JOURNAL AND PROCEEDINGS. 65 
thawing and dissolving of glaciers which are supposed to have 
existed in the frigid epoch of the terrestrial development. 
About 6 weeks ago several children returning from school in 
the evening spoke of having watched on the grassy lawn an assem- 
blage of insects that one of the scholars termed ‘‘ dancing flies.” 
Sometimes as many as eight or ten groups of these gyrating gnats 
are to be seen in the limits of a half acre field on a calm afternoon 
but more frequently in the autumnal season than at any other time 
of the year. The harmonious, gentle, rhythmical movements of the 
coterie it isimpossible to look at without interest and wonder. 
Each gnat moves in an orbit of a certain form ; a sort of elongated 
ellipse. There are hundreds of individuals or more in each coterie 
or ftaternity, evidently inspired by a communistic aim; as in the 
dance of the (so called) superstitious “Shakers.” Like humanity 
the gnat activities for the occasion tend to one corporate aim and 
like the orbits of the asteroids there seems to be a common centre 
or focus and the original point of departure (disruption) is returned 
to. | There is in all the mazy movement no real erraticism, but an 
evident pre-determined ideal, as in the spider’s geometric web. The 
music, too fine for most human ears, but like the hum of the mos- 
quito capable of expressing extremes of sentiment or emotion, isa 
low hum of vibratory wings, as the assemblage rises to its apogee or 
perigee, one or two feet, then simultaneously (like a swarm of bees) 
‘drops to the lower level or segment of the orbitual curve and thence 
gracefully ascends to the appointed altitude of the living garland. 
How so frail an atom of life is perpetuated in spite of extremes of 
solar heat and wintry blizzards seems miraculous, yet their permanence 
and capacity for enjoyment is evidently as well assured as the ele- 
ments, as the rocks and woods and running waters. These gyrating 
gnats seem to find food, shelter and protection (like the aphides) 
on the under mildewed surfaces of grass and wet leaves about fences, 
or under the shade of groves, and like their relative the mosquito 
it is likely that water puddles and marshy areas are their essent- 
ials for reproduction ; although another cousin (i. e. the wheat midge) 
is independent of the aqueous elements as a nidus for its larvae and 
‘finds a nidus in the delicate germs of wheat blossoms. 
The destructive Hessian fly, too, appears to be a relative of the 
