218 ENTOMOLOGICAL NEWS. [May, ’o8 
Migrating Butterflies. 
By P. A. SAVERNER, Highland Park, Mich. 
Point Pelee is a long, tapering point of land, extending from 
the north shore of lake Erie, about nine miles, near the west- 
ern extremity of the lake. Out from the Point lie various 
islands situated like stepping stones across the lake to the Ohio 
shore. Along this point and its outlying islands, lies a great 
natural migration route, followed by birds on their vernal 
and autumnal migrations. During the last three falls I have 
done considerable ornithological work on the Point, and 1 
have been much interested in observing that not only do birds 
habitually use this natural highway in crossing the lake, but 
that there is a regular and well defined stream of Lepidoptera 
flowing across in the fall. In the fall of 1905 during our stay 
from September 4th to 15th, we were greatly astonished at 
the numbers of Anosia plexippus present. They were to be 
seen everywhere, in ones, twos or dozens. In the woods, over 
the fields or along the roadside, and every here and there on 
the edges of the woods a tree would be found covered with 
them. One day, along the east beach, one of the few of the 
small cottonwoods that grow along the top of the sand dune 
was so covered with them that the whole lee side was a mass 
of red, their numbers almost hiding the green foliage com- 
pletely. When we shook the tree they rose in the air in such 
a cloud that they could scarcely be seen through. We never 
saw them flying in flocks except when disturbed in some such 
manner as described above, when they would either fly to an- 
other adjoining tree in a straggling disorganized fashion or 
gradually scatter, and proceed, each insect for itself. Individ- 
uals seldom passed a resting flock but generally joined it and so 
it seemed that the flocks were built up by the gradual accession 
of stragglers. 
The next year from September 15th to 22d, we saw the same 
thing but on not quite so great a scale, due likely to the late- 
ness of the date. : 
This last fall from August 24th to September 6th they were 
nearly as numerous as during the first season, though we saw 
