282 
COLOUR IN NATURE 
CHAP. 
Markings of Kingfishers 
Blue and green structural colours are admirably 
displayed in the family of the kingfishers, which 
show also a gradual progression of colour. Thus in 
Ceryle rudis the feathers are dark brown or black, 
more or less irregularly spotted with white, but with 
the white showing a distinct tendency to form a 
transverse band at the tip of the feather. In Ceryle 
guttata the feathers are regularly cross-barred with 
dull blackish-brown and white. In Carcinentes 
melanops in the wing-coverts the covered part of the 
feather is striped black and white, but the terminal 
bar of white is replaced by blue. In the tail-quills 
the under surface is usually black and white and the 
upper surface blue and black. Where there is partial 
overlapping of the quills, one side of the vane may 
be black and white and the other exposed side black 
and blue. The blue patches occur in positions 
corresponding to the white ones, but are larger and 
show a tendency to fuse together. In the case of 
quill-feathers, the blue is confined to the barbs but 
the barbules are still present, and their dull colour 
somewhat diminishes the brilliancy of the blue. On 
the general contour-feathers, on the other hand, the 
development of the blue colour is associated with a 
suppression of the barbules, while the barbs as usual 
tend to become dilated and polished. 
While in many kingfishers blue and black are the 
dominant colours, in some the blue is replaced by 
green. Thus in Halcyon lindsayi a yellow colour is 
common on various parts of the feathers, and where 
