18 CONTROLLED NATURAL SELECTION 
that position. Animals in defence, in order to 
beat off an enemy, will erect combs, feathers, 
or hairs, will open mouths, stretch necks, take 
up an upright position, and in many other 
ways assume conspicuous attitudes; these 
may be called Repelling Conspicuous Atti- 
tudes. Just as there are attracting conspicuous 
movements, so there are attracting conspicuous 
attitudes. Manyanimals by thus making them- 
selves conspicuous endeavour to draw an 
enemy’s attack, for instance, from their young. 
Birds especially will erect combs, spread tails, 
and assume all manner of conspicuous attitudes 
for this purpose. A large number of pre- 
copulatory displays consist in the assumption 
of conspicuous attitudes. 
Sound.—Sound is seldom used for ought 
but signalling to friend or foe. Silence spells 
concealment, sound conspicuousness. 
Sound can be similarly classified : 
(a) Between the sexes. 
Eade (2) Between members of other 
1, Signals to | 
Purposely societies. 
conspicuous (a.) Repellent (conspicuous) 
sounds. sounds: to frighten an 
2. Signals to} enemy away. 
enemies. |(d) Attractive (conspicuous) 
sounds: to attract an enemy, 
to draw its attack. 
