228 NORTH AMERICAN INSECTS. 
Some years ago we observed multitudes of these insects 
emerging from the Raritan. River, in New Jersey, near 
Trenton, but-never have seen such an enormous quantity of 
them as we once witnessed near the city of St. Petersburg, 
in Russia. We were crossing the River Neva in a little 
row-boat, and encountered probably hundreds of millions. 
The whole atmosphere from one shore to the other was 
filled with them, and from Lake Ladoga down to St. Peters- 
burg, as far as Oranienbaum. The light of the sun was 
intercepted as in a thick fog, so much so that nothing could 
be distinguished at a distance of a few yards. The atmos- 
phere had something the appearance it presents in a violent 
snow-storm, and thousands of day-flies fell into the boat 
and all over our persons, while the fishes in the water, the 
birds in the air, and the domestic fowls upon the shore were 
every where feasting upon them. 
In the evening these flies are strongly attracted toward 
a light, perhaps more so than any other nocturnal insect, 
and it is very amusing to see the crowds of them that fly 
through an open window and dance around the light, mak- 
ing a variety of turns, and circles, and waltzes. They fly 
so close together, and glisten with such splendor, that the 
observer sees a ribbon of gold continually revolving around 
the light, or imagines a celestial globe of living circles re- 
volving in all directions, while the light represents the cen- 
tral sun. This spectacle may be increased to any extent 
in proportion to the number of lights placed in a room, un- 
til the atmosphere be filled with these living miniatures of 
the solar system. 
Butterflies require a considerable time to issue from their 
cocoons, and get their wings dry and expanded for flying ; 
but these little day-flies perform the operation of extricating 
their body, wings, and feet from their pupa, and getting 
ready for their aerial journeys, in less time than a man 
occupies in taking off his coat. And wonderful as is the 
