WHERE SWALLOWS ROOST 108 
to observe.*® This habit does not appear to have 
been previously recorded, and I am by no means 
certain that the explanation offered is the true 
one. 
Frequently one or more flocks, varying in size 
from eight or ten to several hundred birds, may be 
seen in the road, where I at first supposed they were 
“dusting,” but soon noticed that most of the birds 
after alighting in the road were motionless. They 
did not move about as though searching for food, 
but occasionally the actions of a pair enabled one 
apparently to determine the sex of each individual, 
and more often a bird would pick up a bit of dried 
grass and fly up into the air with it. Sometimes it 
was carried fifty yards or more and then dropped; 
at others, the birds would carry it to the telegraph 
wires above, and drop it after perching a moment. 
Without exception, all the birds seen to alight in the 
road were in the dull, immature plumage of birds of 
the year, and in their actions, as Mr. William Brew- 
ster has remarked (The Auk, 1898, p. 194), they evi- 
dently gave a premature exhibition of the procrea- 
tive and nest-building instincts.” 
Additional evidence of the possession of inher- 
ited knowledge was apparently given by many Tree 
Swallows, who were frequently seen hovering about 
a pile standing in the creek.” At first it was sup- 
posed that these birds were feeding on insects which 
had alighted on the pile; but the number of birds— 
often a dozen or more—seen fluttering about it, and 
the persistency with which they remained there, 
forced the conclusion that in a wholly unreasoning 
way they were looking for a nesting site. 
