Chaet^ira T>elagioa . 
Concord., 
1893. 
Aug . 24 . 
Aug . 27 . 
Mass . 
Again great numbers of Swifts at Beaver Dam and Rice Is- 
land but nowhere else a single bird. Their marked preference 
for these stretches of river must be connected in some way 
with the presence of the wild rice which in both places forms 
extensive beds while elsewhere it merely fringes the banks. 
/ 
There were four Martins with the larger flock of Swifts and 
Swallows of three or four species in each. The Swifts dashed 
about at such tremendous speed and passed or crossed one 
another's lines of flight so closely that it seemed wonderful 
that they did not occasionally come into collision. Repeat- 
edly this afternoon, as well as on many other occasions of 
late, a bird flying at full speed and passing close over my 
head made, with its wings doubtless, a peculiar sound very 
like that of a humming top. Only a small proportion of the 
total number made this sound which, by the way, I do not re- 
call ever hearing except at about this season, perhaps it is 
JJTroduced only by the young or by adults at a certain stage of 
the moult when the wings are lacking a portion of the quills. 
On several occasions this summer when a thunder shower 
was coming up I have noticed Swallows and Swifts flying at a 
great height. Two Swifts this afternoon were wheeling about 
along the edge of the thunder cloud at fully 2000 ft. above 
the earth. They appeared to be feeding. 
