CHAPTER VI 



DEFENCES OF INSECTS, OR PROTECTION AS DERIVED 

 FROM COLOUR 



Need of insects of means of defence Adaptation of their exter- 

 nal colouring to conditions of life Protective Resemblances 

 herein find explanation of first and most widespread use 

 of colour among animals Principle of adaptive colouring 

 solved by theory of natural selection Commonness of 

 general harmony between colouring of insects and tints of 

 nature Imitative tints of undersides of wings of butterflies 

 Special Protective Resemblance 'stick-caterpillars 'and 

 others leaf-butterflies British and European moths 

 among Orthoptera tropical " walking-leaf" and " walking- 

 stick " insects other insects and spiders Alluring colour- 

 ing Resemblance of Mantises and spiders to flowers to 

 excreta of birds Changes of colour corresponding to 

 changes of environment Di- and Polymorphism their 

 value meaning obscure Variable Protective Resemblance 

 in pupae in larvae in colours of cocoons in perfect 

 insects Variable Protective Resemblance and the origin 

 of colour Power of adjustment of colour is adaptive, and 

 is produced and maintained by natural selection. 



IT is unnecessary to enlarge upon an insect's need of 

 means of defence. Obviously no creature could be 

 more open to attack, and added to its peculiarly 

 defenceless condition on all hands innumerable 



