40 



SOME SOUTH INDIAN INSECTS, ETC. 



ICHAP. IV. 



extremity of the butterfly, the flaps themselves looking like a 

 head and the spots and long slender tails simulating eyes and 

 antenna;; the anterior extremity (head, antennre, etc.) is incon- 

 spicuously coloured and the apex of the abdomen does not extend as 

 far as the false head, so that an enemy such as a lizard, seeing the 

 butterfly at rest, in attacking the supposedly vital anterior 

 extremity, would obtain only a mouthful of hindwing, the butterfly 

 escaping without vital injury. A collection of butterflies made at 

 random, without regard to the " cabinet condition " of the speci- 

 mens caught, will soon convince any impartial observer that such 

 directive markings do actually exhibit signs of attack by enemies 

 (chiefly birds and lizards). 



Fig. 21. — Viracholct isocrates, a Lyceenid Butterfly, in its resting attitude 

 showing simulation of the head by the tails and eye-spots, which | 

 well clear of the body. The right-h i ws .1 view of tin butterfly 



at rest as seen from behind, showing the anal lobes and tin in. mini in which 

 the tails are projected on opposite sides. (Original.) 



Insects which exhibit "warning" coloration may acquire a 

 nauseous taste from feeding on plants which are poisonous to 

 vertebrate animals or from other causes. The rich colours of the 

 scales of some butterflies are known to he due to the deposition of 

 waste materials (of the nature of urates) of the excretorj SJ Stem ami 

 it seems possible that in other cases, in which the insects f< 

 non-poisonous plants, their nauseous qualities maj he derived from 

 the retention and use in this way of waste products of the processes 

 of metabolism. 



From warning colours and innate nauseous qualities it is but a 

 step to cases in which insects actually excrete substances which 



