86 CONTROLLED NATURAL SELECTION 
may be again sub-divided as in the following 
table : 
to enemies | protective=procryptic. 
inconspicuous to food aggressive =anticryptic. 
(to friends) | (? valueless.) 
COLOUR 
to attract enemies= 
attracting colour. 
to signal to 
enemies 
to repel enemies 
= Aposematic. 
= Pseudo-sematic. 
conspicuous 
to signal to | Recognition marks 
friends = Episematic. 
to attract food (as in 
to signal to Mantidz) 
food = Pseudo-episematic. 
=alluring colour. 
The colour of an animal can, however, never 
be considered as a unit. Some ofthe coloured 
parts will be used for one purpose, others for 
another. ‘or instance, in many animals and 
especially in birds, parts are conspicuously 
coloured which are usually concealed, and 
which are only displayed on definite occa- 
sions and for definite purposes : thus, too, the 
Red Admiral butterfly can, at will, display 
