GRADATION OF CHARACTERS. 
135 
’ Ul ‘' SIV. 
9,1'g 
k a SUr r°unded by many successive zones of colour, 
b ea e lje <m generated, I will not pretend to say. But 
ofc/ 11 ^ i ' 1 mind the zoned feathers of the mongrel 
o t( j! lrin S from differently-coloured fowls, and the extra- 
t ] 1(1 ^ ir y Variability of the ocelli in many Lepidoptera, 
lj fe „ Ration of these beautiful ornaments can hardly 
s nili _ %hly complex process, and probably depends on 
tiss Ues U and g. ra( j ua ted change in the nature of the 
n 
of , of Secondary Sexual Characters. Cases 
it Nation are important for us, as they shew that 
^ ^ast possible that highly complex ornaments 
hi , llVe been acquired by small successive steps. 
iyi^i lf to discover the actual steps by which the 
e o«t ° f aUy existiu g bird has acquired his magnifi- 
^ c °l°Urs or other ornaments, we ought to behold 
W t boo of his ancient and extinct progenitors; 
gene, i is obviously impossible. We may, however, 
u Sain a clue by comparing all the species of 
if it be a large one ; for some of them will 
their c y vetHil b at least in a partial manner, traces of 
fletai] ° riDer characters. Instead of entering on tedious 
in ^ 1 S res pecting various groups, in which striking 
Man UOeS °f gradation could be given, it seems the best, 
cas c . s t0 ta ke some one or two strongly-characterised 
c^’ , 01 ’ instance that of the peacock, in order to dis- 
"bicl a . ny light can thus be thrown on the steps by 
b’ke 1 bir l has become so splendidly decorated. 
o tcli b eac oek is chiefly remarkable from the extra- 
lei^'y length of his tail-coverts; the tail itsell not 
"'hof ^ Ucl1 e l°ngated. The barbs along nearly the 
c] 6( . 0 ° l en gth of these feathers stand separate or are 
of i ^ r 'b°sod ; bu t this is the case with the feathers 
U "y species, and with some varieties of the 
