THE PASSING OF THE BIRDS. 189 
ment northward or southward. We see the 
stragglers, more or less numerous, that hap- 
pen to have dropped out of the procession in 
our immediate neighborhood, —a flock of 
sandpipers about the edge of the pond, some 
sparrows by the roadside, a bevy of war- 
blers in the wood, —and from these signs 
we infer the passing of the host. 
Unlike swallows, robins, bluebirds, black- 
birds, and perhaps most of the sparrows, our 
smaller wood birds, the warblers and vireos 
especially, appear to move as a general thing 
in mixed flocks. Whenever the woods are 
full of them, as is the case now and then 
every spring and fall, one of the most strik- 
ing features of the show is the number 
of species represented. For the benefit of 
readers who may never have observed such 
a “bird wave,” or “rush,” let me sketch has- 
tily one which occurred a few years ago, on 
the 22d of September. As I started out at 
six o’clock in the morning, in a cool north- 
west wind, birds were passing overhead in 
an almost continuous stream, following a 
westerly course. They were chiefly war- 
blers, but I noted one fairly large flock of 
purple finches. All were at a good height, 
