108 CONTROLLED NATURAL SELECTION 
The following method of placing the birds 
in the tables is employed. Birds presenting 
defined, unconcealed, flat areas of red, blue, 
yellow, black or white are placed under “at- 
tracting”; the rest under “cryptic.” In a 
few cases difficulties arise; for instance, the 
Ring Dove (C. palumbus) has a small white 
patch on either side of the neck, and should 
therefore have been placed under “ attract- 
ing”: but because the area of white is, com- 
pared to the bird, very small, and the bird 
otherwise undoubtedly cryptically coloured, 
it has been placed under “ cryptic.” 
Division I 
Birds of Prey.—See Table I. 
Without exception, none of these birds 
present conspicuous colouring because they 
are not liable to be attacked. They require to 
be cryptically coloured so as to be able to 
approach their prey unobserved. The sexes 
are similar, therefore males are not espe- 
cially destroyed, and polygamy does not 
occur. 
Night Birds.—See Table IT. 
These are, without exception, cryptically 
coloured ; attracting colour for the protection 
