INSECT LIFE 197 



protects it thus, why not the adult ? I am not 

 much embarrassed myself, because I have not hugged 

 the protective theory in all these matters very fondly. 

 Say, however, one does believe absolutely in the pro- 

 tective theory here ; then I suggest this as a possible 

 way round the difficulty raised by the stolid behaviour 

 of the full-grown caterpillar. The caterpillar is now 

 almost two inches in length, and armed all over with 

 black spines or bristles. It is said the cuckoo is one 

 of the few English insect-eating birds that will tackle 

 large bristly caterpillars. So, perhaps, the peacock 

 caterpillar, when full grown, is no longer in danger of 

 being eaten by enemies; and, therefore, it need not 

 hastily tumble off its leaf and die. No doubt it needs 

 a somewhat lively imagination to agree to this change 

 in caterpillar habit ; but how otherwise may one 

 account for the fact that the baby shams death for 

 protective purposes, whilst the adult does not ? 



The peacock butterfly caterpillar at this spiney 

 state of life is much better-looking than it promised 

 to be in babyhood. Besides its bristles, it has neat, 

 regular lines of white spots, somewhat like tiny silver 

 sequins sewn on some velvet material of a lady's 

 evening dress, and its legs are reddish. The decora- 

 tion of a caterpillar and the way in which with some 

 kinds of caterpillars this decoration varies according 

 to the age of the grub is a most recondite matter. 

 There is no courtship or rivalry for a caterpillar. The 

 sexual motive does not come in. Yet it is impossible 



