r 26th, in four flocks,
succeeding each other at intervals of a few minutes, and numbering in
all about 130 birds. They flew directly south, at a moderate height,
and were almost certainly detachments of one body. The bluebird movement
was two days later, at about the same hour, the morning being cold, with
a little snow falling. This time, too, as it happened, the flock was in
four detachments. Three of these were too compact to be counted as they
passed; the fourth and largest one was in looser order and contained a
little more than a hundred individuals. In all, as well as I could
guess, there might have been about three hundred birds. They kept a
straight course southward, flying high, and with the usual calls, which,
in autumn at least, always have to my ears a sound of farewell. Was it a
mere coincidence that these swallows, bluebirds, and robins were all
crossing the valley just at this point?

This question, too, I count it safer to ask than to answer, but all
observers, I am sure, must have remarked so much as this,--that birds,
even on their migrations, are subject to strong local preferences. An
ornithologist of the highest repute assures me that his own experience
has convinced him so strongly of this fact that if he shoots a rare
migrant in a certain spot he makes it a rule to visit the place again a
year afterward on the same day, and, if possible, at the same hour of
the day. Another friend sends me a very pretty story bearing upon the
same point. The bird of which he speaks, Wilson's black-cap warbler, is
one of the less common of our regular Massachusetts migrants. I count
myself fortunate if I see two or three specimens during its spring or
autumn passage. My correspondent shall tell the story for himself.

"While I was making the drawings for the 'Silva,' at the old Dwight
house, I was in the habit of taking a turn every pleasant day in the
gardens after my scanty lunch. On the 18th of May, 1887, in my daily
round I saw a Wilson's black-cap for the first time in my life. He was
in a bush of _Spiraea media_, which grew in the midst of the rockery, and
allowed me to examine him at near range with no appearance of fear.
Naturally I made a note of the occurrence in my diary, and talked about
it with my family when I got home. The seeing of a new bird always makes
a red-letter day.

"The next spring, as I was looking over my notebook of the previous
year, I came upon my entry of May 18th, and thought I w