The Making of Species 



another genus which vibrates its tail among dry 

 leaves, and thus produces a warning sound. 

 The deadly little Indian snake (Echis 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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