The Mason-bees 



how comes it that the denizen of the sun- 

 blistered rocks persists in his blue and green 

 colouring, which at once betrays him against 

 the whity-grey stone ? Indifferent to mimicry, 

 is he the less skilful Beetle-hunter on that 

 account, is his race degenerating? I have 

 studied him sufficiently to be able to declare 

 with positive certainty that he continues to 

 thrive both in numbers and in vigour. 



Why has the Spurge-caterpillar adopted 

 for its dress the gaudiest colours and those 

 which contrast_ most with the green of the 

 leaves which it frequents? Why does it 

 flaunt its red, black and white in patches 

 clashing violently with one another? Would 

 it not be worth its while to follow the exam- 

 ple of the Cabbage-caterpillar and imitate the 

 verdure of the plant that feeds it? Has it no 

 enemies? Of course it has: which of us, ani- 

 mals and men, has not? 



A string of these whys could be extended 

 indefinitely. It would give me amusement, 

 did my time permit me, to counter each ex- 

 ample of protective mimicry with a host of 

 examples to the contrary. What manner of 

 law is this which has at least ninety-nine ex- 

 ceptions in a hundred cases? Poor human 



