THE PURPLE MARTIN. 
171 
10th or 15th of April, and sometimes suffer from unexpected returns of 
frost. At Philadelphia, they are first seen about the 10th of April. They 
reach Boston about the 25th, and continue their migration much farther 
north, as the sprang continues to open. 
On their return to the Southern States, they do not require to wait for 
warmer days, as in spring, to enable them to proceed, and they all leave the 
above-mentioned districts and places about the 20th of August. They assem- 
ble in parties of from fifty to a hundred and fifty, about the spires of churches 
in the cities, or on the branches of some large dead tree about the farms, for 
several days before their final departure. Prom these places they are seen 
making occasional sorties, uttering a general cry, and inclining their course 
towards the west, flying swiftly for several hundred yards, when suddenly 
checking themselves in their career, they return in easy sailings to the same 
tree or steeple. They seem to act thus for the purpose of exercising them- 
selves. as well as to ascertain the course they are to take, and to form the 
necessary arrangements for enabling the party to encounter the fatigues of 
their long journey. Whilst alighted, during these days of preparation, they 
spend the greater part of the time in dressing and oiling their feathers, clean- 
ing their skin, and clearing, as it were, every part of their dress and body 
from the numerous insects which infest them. They remain on their roosts 
exposed to the night air, a few only resorting to the boxes where they have 
been reared, and do not leave them until the sun has travelled an hour or 
two from the horizon, but continue, during the fore part of the morning, 
to plume themselves with great assiduity. At length, on the dawn of a 
calm morning, they start with one accord, and are seen moving due west 
or south-west, joining other parties as they proceed, until there is formed 
a flock similar to that which I have described above. Their progress is 
now much more rapid than in spring, and they keep closer together. 
It is- during these migrations, reader, that the power of flight possessed 
by these birds can be best ascertained, and more especially when they 
encounter a violent storm of wind. They meet the gust, and appear to 
slide along the edges of it, as if determined not to lose one inch of what 
they have gained. The foremost front the storm with pertinacity, ascending 
or plunging along the skirts of the opposing currents, and entering their 
undulating recesses, as if determined to force their way through, while the 
rest follow close behind, all huddled together into such compact masses as 
to appear like a black spot. Not a twitter is then to be heard from them 
by the spectator below ; but the instant the farther edge of the current is 
doubled, they relax their efforts, to refresh themselves, and twitter in united 
accord, as if congratulating each other on the successful issue of the contest. 
The usual flight of this bird more resembles that of the Hirundo urbica 
