MIGRATION AND DISPERSAL OF INSECTS; LEPIDOPTERA. 207 
221) that at West River, Maryland, about 7 o’clock in the morning, 
his attention was called to the fact that ‘‘ the whole heavens were 
swarming with butterflies.” There was ‘‘an innumerable number of 
them at all heights, from 100 feet to a height beyond the range of 
vision except by the aid of a glass. They were flying due south-west 
in the face of a stiff breeze. Observations upon the flight of 
individuals, between points of known distances apart, showed that the 
rate of movement was not far from twenty miles an hour. Where 
they originally came from or whither they went we could not tell. 
They undoubtedly came from beyond the bay, w hich, in that place, is 
fourteen miles across, and they must have been early on the wing. 
By 11.80 a.m. the numbers had declined, and it was evident that the 
bulk of the flight was over, but for several days a great many 
individuals, evidently followine o the migrating movement, were 
observed.” Two days later (September 25th, 1886) a report from 
Maryland (Baltimore County) states that a vast multitude of the same 
butterflies were seen ‘‘in migratory movement.’’ They were seem- 
ingly exhausted in flight, and settled on the trees in such multitudes 
as to give them the appearance of an autumnal frost. Andras reports 
that in September, 1887, about the heads of the Saskatchewan River, 
shrubs and small trees were covered with them in countless numbers. 
In the cool (almost frost) of the evening they could be shaken to the 
ground in a helpless, chilled condition, “but. ‘were lively enough when 
the sun warmed them. He further adds that “the Cree and Blackfeet 
Indians say the wind from the south brings them there.’” Another 
report from Hampton (New Hampshire), by Scudder, states that, on 
September 2nd, 1888, when only a stone’s throw from the water, 
continuous streams of A. archippus passed towards the south-west, 
following the line of the sea-coast, with the wind about north-west. 
It was calculated that some fifteen hundred passed the observer in a 
very short time. In 1892, a year in which this species appears to 
have been exceptionally abundant, in Ohio and Northern Indiana, the 
following report relating to the appearance of the insect was sent to 
Insect Life: “On September 19th, in the afternoon, a multitude of 
butterflies visited Cleveland on their way south. There were swarms 
upon swarms of them, and, for a while, they completely filled the air. 
They were of the large ho n variety of the Milkweed butterfly, and it 
1s supposed that they were started by the storms in the east. Such 
migrations, although not unusual in the south and west, are very 
uncommon in this part of the country.” Dr. Neal also reports (loc. 
cit., v., p. 197) that, on October 4th, 1892, he saw a swarming or 
migration OL Ae archippus, near Okhahoma, Texas, finding «hundreds 
of these butterflies roosting at 8 p.m. They were as thick as the 
leaves on the shrubs. At 9 a.m. next mornine they took to the ai, 
and, as far as one could see east and west, from 40 to 200 feet above 
the ground, the butterflies were flying to the south, apparently one 
every few feet; often a cloud of several hundreds would pass almost 
in a sohid body, enough to cast ashadow. At 2 p.m. they diminished in 
numbers and flew lower down. From the best information that could be 
obtained this swarm extended twenty miles east and west, and were in 
motion steadily southward from 8 a.m. to 3 p.m. On October 6th, a 
smaller swarm was seen, from 10 a.m. until 3 p.m.” ‘The observer 
adds that ‘no one here recollected seeing such a migration before.” 
