DECORATION. 
Ch. 
At>. 
XIII. 
I 6 
w °uld impede the act of flight. Yet the 
^tfuUy ocellated secondary wing-feathers of the 
^ Argus pheasant are nearly three feet in length; 
n ' C 111 a small African night-jar ( Cosmetornis vexilla- 
bi^'^i - 0116 ^ ie primary wing-feathers, during the 
Reason, attains a length of twenty-six inches, 
j n ’ st Hie bird itself is only ten inches in length. 
of ^°tiier closely-allied genus of night-jars, the shafts 
tl | 6 0 ^Dgated wing-feathers are naked, except at 
^ot-remity, where there is a disc . 14 
Again, in 
s till * S enus of nightjars, the tail-feathers are even 
Hill] ° 
^ lrj °re prodigiously developed ; so that we see the 
111 kind of ornament gained by the males of closely- 
birds' 
f «ath 
It 
to 
fhe 
in 
Is, through the development of widely different 
'erg. 
18 a curious fact that the feathers of birds belonging 
groups have been modified in almost exactly 
Sam e peculiar manner. Thus the wing-feathers 
°Ue of r[ U; above-mentioned night-jars are bare 
tl 1(? & tUe shaft and terminate in a disc; or are, as 
J J are sometimes called, spoon or racket-shaped. 
lers of this kind occur in the tail of a rnotmot 
^ota swper ciliar is), of a king-fisher, finch, burn- 
ed P iUTot > several Indian drongos ( Dicrurus 
anfl • °^ MS > in one of which the disc stands vertically), 
UttJ 11 ^' e ta ^ certa i n Birds of Paradise. In these 
o lT| , 01 kirds, similar feathers, beautifully ocellated, 
ga]| U ‘"‘ ut the head, as is likewise the case with some 
a W) . 0la, ' <!o ns birds. In an Indian bustard ( Sypheotides 
ab 0( Us ) ^ le feathers forming the ear-tufts, which are 
1 i°ur inches in length, also terminate in discs . 03 
tio >i to ti tei r’ in tlle ‘ tbis,’ vol. vi. 1864, p. 114. Livingstone, ‘ Expedi- 
65 Jev.in Zaml,e “V 1865, p. 66. 
n ’ ‘Birds of India,’ vol. iii. p. 620. 
