OilAP. XIII. 
INSTRUMENTAL MUSIC. 
65 
Fig. 44. Primary wing-feather of a 
Humming-bird, the Selasphorus pla- 
tycerus (from a sketch by Mr. Sal v in). 
Upper figure, that of male ; lower 
figure, corresponding feather of fe- 
male. 
species is known to make a humming noise w^hilst 
courting the female. In a widely different group ot 
birds, namely the Humming-birds, the males alone 
of certain kinds have either 
the shafts of their primary 
wing-feathers broadly dilated, 
or the webs abruptly excised 
towards the extremity. The 
male, for instance, of Selaspho- 
rus platycercus, when adult, 
has the first primary wing- 
feather (fig. 44), excised in 
this manner. Whilst flying 
from flower to flower he 
makes a shrill, almost whistling, noise ; ” but it 
did not appear to Mr. Salviir that the noise w^as inten- 
tionally made. 
Lastly, in several species of a sub-genus of Pipra or 
Manakin, the males have their secondary wing-feathers 
modified, as described by Mr. Sclater, in a still more 
remarkable manner. In the brilliantly-coloured P. 
deliciosa the first three secondaries are thick-stemmed 
and curved towards the body ; in the fourth and fifth 
(fig. 45, a) the change is greater ; and in the sixth 
and seventh (I, e) the shaft “ is thickened to an 
extraordinary degree, forming a solid horny lump.” 
The barbs also are greatly changed in shape, in com- 
parison with the corresponding feathers (d^ e, f) in the 
female. Even the bones of the wing which support 
these singular feathers in the male are said by Mr. 
Fraser to be much thickened. These little birds make 
; Jerdon, ‘ Birds of India,’ vol. iii. p. 618, 621. 
Gould, ‘ introdnetion to the Trocliilidse,’ 1861, p. 49. Salvin, 
^ Proc. Zoolog. Soe.’ 1867, p. 160. 
VOL. II. 
F 
