324 THE PLACE OF MnUCRY 



to assume a position in which their characters are dis- 

 played to tlie full. Thus Portschinski has shown that 

 the two unpalatable Enorllsh moths Spilosoma nrticac^ 

 and S. fnendica*, female, when disturbed, assume attitudes 

 which serve to dispku their cons|)icuous yellow and black 

 colours.* In boih types of so-called 'sham death' — 

 Cryptic and Aposematic — a defmite attitude is assinned, 

 which is not that of death. 



9. IVarfiifii^ or IiiliniidatiiiQ^ Sounds. — Sound may be 

 employed as an Aposematic Character, as in the hiss of 

 snakes and some lizards. Certain poisonous snakes when 

 disturbed produce by an entirely different method a far- 

 reachincf sound not unlike the hiss. Thus the Rattle 

 Snake (Ciofa/us) of America rapidly vil)rates the series 

 of dr\', horny, cuticular cells, movably articulated to each 

 other and to the end of the tail. The staue throujjh 

 which the character probabl)- arose is witnessed in 

 another genus which vibrates its tail among dr}' leaves 

 and thus produces a warning sound. The deadl}' little 

 Indian snake, Echis cari)iata (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 the\' are rubbed airainst each other. Lar^e 

 birds, when attacked, often adojjt a threatening attitude 

 accompanied by an intimidating soimd which usually 

 suggests more or less closely the hiss of a serpent, and 

 thus includes an element of Mimicry. 



10. Intimidating^ Attitudes. — Ihe Cobra warns an 

 intruder chiefly by attitude and by the broadening of its 

 flattened neck, tlu! eftect beini: heiirhtened in some 

 species by the 'spectacles'. In such cases we often 

 witness a combination of Cryptic and Aposematic 

 methods, the animal being concealed until disturbed, 

 when it instantly assumes a Warning attitude. 



The benefit of such intimidating characters is clear: 

 a venomous snake gains far more advantage by terrifying! 

 than by killing an animal it cannot eat. By striking, 

 the serpent temporarily loses its poison and with this] 



' Ltpidopkrorian Rossiae Biologia, St. Petersburg, 1890. 



I 



