66 
SEXUAL selection: bikds. 
Part II„. 
an extraordinary noise, the first sharp note being not 
unlike the crack of a whip/’ 
cl e f 
Fig. 45. Secondary wing-feathers of Pijgra deliciosa (from Mr. Sclater, in Proc. Zool. Soc. 
1860). The three upper feathers,, a, h, c, from the male ; the three lower corresponding 
feathers, d, e,f, from the female. 
a. and d. Fifth secondary wing-feather of male and female, upper surface. h and <?. 
Sixth secondary, upper surface. c and/. Seventh secondary, lower surface. 
The diversity of the sounds, both vocal and instru- 
mental, made by the males of many species during the 
Sclater, in ‘ Proc. Zool. Soe.’ 1860, p. 90, and in ‘ Ibis,’ vol. iv.. 
1862, p. 175. Also Salvin, in ‘ Ibis,’ 1860, p. 37. 
