432 
SAVAGE SUDAN 
of modern zoological science—there remains another aspect 
that needs a moment’s examination. Not only are the defence¬ 
less presumed to be protected against potential enemies, but 
the enemies also, that is the Raptorials, are camouflaged in turn. 
Now in the Sudan raptorials abound—man, bird, and beast alike 
prey on feebler neighbours. Along the Nile stretch predacious 
multitudes in serried ranks unbroken for thousands of miles. 
The main objectives of these bandits are virtually identical. 
In order that they may live, ten, or a hundredfold their numbers 
of other creatures must die daily—flesh, fish, reptile—with all 
the host of strange amphibian beings that abound in mud- 
charged shallows and reed-studded swamp. True, it is a 
“soft-job”; but, even so, 
when objectives are equal, 
why should the aggressors 
be arrayed in diametrically 
opposite colours ? There 
are, for example, four 
species of ibis; two are 
white, the other two black. 
The same rule applies to 
the herons, egrets, storks 
—to the whole category. 
By theory, if the white are 
“ Rippling Plumes.” specially equipped for their 
work, the black must be 
proportionately handicapped. In practice, both succeed equally. 
The white prosper; the black never lack. Colour does not 
count. 
The common British heron is extolled as a masterpiece of 
concealing coloration. His dappled array of pectoral plumes, 
it is claimed, so admirably resemble rippling water as to 
deceive the very fish themselves. Well, the British heron is 
equally common here on Nile—ripples and all; but here he 
finds two cousins—keen competitors in piscatorial pursuits— 
but which, instead of rippling plumes, display solid dark 
waist-coats of deep maroon-red. They, too, find no difficulty 
in getting their daily bread; nor do the egrets, which 
are snow-white; nor the openbill, which is glossy black. 
None have rippling plumes designed to deceive; yet towards 
