The Making of Species 
another genus which vibrates its tail among dry 
leaves, and thus produces a warning sound. 
The deadly little Indian snake (Zchzs carinata) 
(‘the Kuppa’) makes a penetrating swishing sound 
by writhing the coils of its body one over the 
other. Special rows of the lateral scales are 
provided with serrated keels which cause the 
sound when they are rubbed against each other. 
Large birds, when attacked, often adopt a 
threatening attitude, accompanied by an intimi- 
dating sound which usually suggests more or less 
closely the hiss of a serpent, and thus includes an 
element of mimicry. . . . The cobra warns an 
intruder chiefly by attitude and by the broadening 
of its flattened neck, the effect being heightened 
in some species by the ‘spectacles.’ In such 
cases we often witness a combination of cryptic 
and Aposematic methods, the animal being con- 
cealed until disturbed, when it instantly assumes 
a warning attitude. 
“ The benefit of such intimidating attitudes is 
clear: a venomous snake gains far more advan- 
tage by terrifying than by killing an animal it 
cannot eat. By striking, the serpent temporarily 
loses its poison, and with this a reserve of defence. 
Furthermore, the poison does not cause imme- 
diate death, and the enemy would have time to 
injure or destroy the snake.” 
At first sight this reasoning may seem very 
convincing. But consider for a moment the 
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