64 
SEXUAL SELECTION : BIRDS. 
Part IL 
He found that by blowing on these feathers, or by fasten- 
ing them to a long thin stick and waving them rapidly 
through the air, he could exactly reproduce the drum- 
ming noise made by the living bird. Both sexes are 
furnished with these feathers, but they are generally 
and in S, javensis (fig. 
Fig. 43. Outer tail-featber Of Scolopax javensis. ^3), nO leSS than eight 
are greatly modified. Different tones are emitted by 
the feathers of the different species when waved through 
the air; and the Seolojpax Wihonii of the United States 
makes a switching noise wliilst descending rapidly to 
the earth. 
In the male of the Chamsepetes unicolor (a large galli- 
naceous bird of America) the first primary wing-feather 
is arched tow^ards the tip and is much more attenuated 
than in the female. In an allied bird, the Penelo]pe 
nigra, Mr. Salvin observed a male, which, whilst it 
flew downwards ^^with outstretched wings, gave forth 
a ki^d of crashing, rushing noise,” like the falling 
of a tree.^^ The male alone of one of the Indian 
bustards (Sypheotides auritus) has its primary wing- 
feathers greatly acuminated ; and the male of an allied 
See M. Meves’ interesting paper in ‘Proc. Zool. Soc/ 1858, p. 199. 
For the habits of the snipe, Macgillivray, ^ Hist. British Birds," vol. iv. 
p. 871. For the American snipe, Capt. Blakiston, ‘Ibis," vol. v. 1863, 
p. 131. 
Mr. Salvin, in ‘ Proc. Zool. Soc." 1867, p. 160. I am much in- 
debted to this distinguished ornithologist for sketches of the feathers of 
the Chamsepetes, and for other information. 
Fig. 42- Outer tail-feather of Scolopax frenata. 
larger in the male than 
in the female, and emit 
a deeper note. In some 
species, as in S, frenata 
(fig. 42), four feathers, 
on each side of the tail 
