SOUNDS THAT CARRY FARTHEST 241 
stands erect, a tall conspicuous object on the wide 
level plain, his long neck inflated and the pinions 
with their white plumes spread open. There had 
been an ostrich hunt that day, and the sounds I 
listened to probably came from two or three birds 
calling from widely separated points. 
We note that in listening to the singing of birds 
the high shrill notes invariably live longest in the 
ears as the distance increases, while the lower gut- 
tural and harsh sounds die successively out of the 
performance. This is most noticeable in the sky- 
lark's torrential song, owing to the great variety of 
notes of different quality composing it. 
The macaws in flocks, uttering their tremendous 
screams when flying high above the forest trees, 
make a great noise, but it does not carry half the 
distance of the bell-bird's metallic, clanging call. 
I remember that in my home on the pampas, when 
I was a boy, we used to stand out of doors on those 
exceptionally still, clear mornings when all distant 
objects seemed near, and when all sounds appeared 
to travel twice as far as at ordinary times. We 
would listen with delight on such mornings, which 
were usually in the winter, to the calls and cries of 
the great water-fowl in three or four rush- and sedge- 
grown lagoons situated at different points and at 
various distances from our home, from something 
over a mile to two miles and a half. From all of 
them we could distinctly hear certain species: the 
alarm cry and song-like perfOrmances of the crested 
screamer; the short, rapidly reiterated call of the 
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