WONDERS OF INSTINCT 209 



head is always turned towards the door." This 

 seems a minute detail, but the strength of a chain 

 is that of its weakest link. The supple grub can 

 turn this way or that in its chamber, but the coming 

 Cerambyx will not be able to turn or bend. " He 

 must absolutely find the door in front of him, lest 

 he perish in the casket. Should the grub forget this 

 little formality, should it lie down to its nymphal 

 sleep with its head at the back of the cell, the Cap- 

 ricorn is infallibly lost; his cradle becomes a hopeless 

 dungeon." But the grub forgets as little as it 

 learns! 



The third feature which Fabre's studies bring 

 into prominence is the limitation of instinct. Often 

 subtle and perfect, without a loose thread from 

 first to last, the instinctive routine often ends in 

 an almost ridiculous fiasco, when a grain of in- 

 telligence would have saved the situation. The 

 fact is, of course, that the instinctive capacity has 

 been slowly and exquisitely adapted for the ninety- 

 nine per cent, of normal circumstances, not to meet 

 the one per cent, of exceptional contretemps. 

 Strange it is, however, that the burying beetles will 

 allow themselves to pine away in an artificial prison 

 which has for such expert tunnel-makers a widely- 

 open door widely open physically, but closed 

 psychically. They often show great pertinacity in 

 trying to bury a mouse in difficult conditions, but 

 Fabre's ingenious experiments showed that they 

 were baffled by simple tricks of suspension where a 

 touch in the right direction would have made the 



