82 MIMICRY AMONGST THE LEPIDOPTEEA. 



a tropical region, where life of all kinds is abundant and 

 the struggle for existence tenfold more keen. Wallace says 

 that " in the Brazilian forests there are great numbers of 

 insectivorous birds — as jacamars, trogons, and puff-birds — 

 which catch insects on the wing, and that they destroy many 

 butterflies is indicated by the fact that the wings of these 

 insects are often found on the ground, where their bodies 

 have been devoured." And, beside the birds, the rapacious 

 dragon-fly follows its flying prey with wings swifter still, 

 whilst the insect at rest on the tree-trunk falls into the 

 power of the spider or lizard, or the mantis lying in wait, 

 disguised as a bundle of leaves, or the phasma lurking 

 among the dead twigs, itself as stick-like as they. From all 

 these dangers, likeness to a species malodorous or dis- 

 tasteful would give to the insect assuming it protection 

 more or less complete : not entire protection, for it has been 

 proved by experiments that the hungry bird or lizard will 

 approach and devour a species which it at first believed to 

 be distasteful, though only after much preliminary care and 

 examination ; so that the temporary hesitation of its foe 

 would in natural conditions give the attacked insect many 

 chances of escape. 



Amongst the Diurnal Lepidoptera we find two families in 

 particular, the Dauaince and Acrceince^ which are distasteful 

 to birds and other animals ; and even apparently after death 

 this characteristic protects their bodies from the inroads of 

 the acarus. Hence, as we might expect, we find that most 

 of the mimicking species bear a resemblance to one of the 

 species of these two families. 



In some cases both sexes share this immunity, but in 

 others the female only is protected by likeness to the 

 nauseous insect ; it being most important to the survival of 

 a species that the lives of the majority of its females should 



