The Mason-Wasps 



seizes the scented creature by the skin of the 

 neck and, despite its sprays of perfume, dis- 

 patches it with a few stings. This was the 

 bandit against whom, above all, it should 

 have defended itself; and the poor grub has 

 not been happily inspired in this respect. 

 Considering the huntress' exclusive taste for 

 this sort of game, we must presume that 

 the Chrysomela's drug-shop possesses a 

 delicious aroma in the Odynerus' opinion. 

 The defensive secretion becomes a deadly 

 bait. Even so with other means of pro- 

 tection: each advantage invariably has some 

 corresponding disadvantage. 



I have read, I forget where, the story of 

 certain South-American Butterflies, some of 

 whom tasted bitter, others not. The first 

 were respected by the birds because of their 

 bitterness; the second were eagerly swal- 

 lowed. What did the persecuted insects 

 do? Unable to acquire the disagreeable 

 flavour of the bitter ones, they at least imi- 

 tated their shape and their costume. And 

 the birds were taken in by the fraud. 



This was put forward as a striking proof 

 of evolution in view of the struggle for life. 

 I am repeating the story more or less cor- 

 rectly, as it lingers vaguely in my memory, 



for I have never attached more import- 

 194 



