148 FABRE'S BOOK OF INSECTS 



safe retreat and face the perils of the outer world. Eating is 

 not everything, after all ; we have to get out of this. 



But how ? For the grub, before leaving the trunk, must 

 turn into a long-horned Beetle. And though the grub, being 

 well equipped with tools and muscular strength, finds no diffi- 

 culty in boring through the wood and going where it pleases, 

 it by no means follows that the coming Capricorn has the same 

 powers. The Beetle's short spell of life must be spent in the 

 open air. Will it be able to clear itself a way of escape ? 



It is quite plain, at all events, that the Capricorn will be 

 absolutely unable to make use of the tunnel bored by the grub. 

 This tunnel is a very long and very irregular maze, blocked 

 with great heaps of wormed wood. It grows constantly 

 smaller and smaller as it approaches the starting-point, because 

 the larva entered the trunk as slim as a tiny bit of straw, 

 whereas to-day it is as thick as one's finger. In its three years' 

 wanderings it always dug its gallery to fit the size of its body. 

 Evidently the road of the larva cannot be the Capricorn's 

 way out. His overgrown antennae, his long legs, his inflexible 

 armour-plates would find the narrow, winding corridor im- 

 passable. The passage would have to be cleared of its wormed 

 wood, and, moreover, greatly enlarged. It would be easier 

 to attack the untouched timber and dig straight ahead. Is 

 the insect capable of doing so ? I determined to find out. 



I made some cavities of suitable size in some oak logs that 

 had been chopped in two, and in each of these cells I placed 

 a Capricorn that had just been transformed from the grub. I 

 then joined the two sides of the logs, fastening them together 

 with wire. When June came I heard a sound of scraping 

 inside the logs, and waited anxiously to see if the Capricorns 

 would appear. They had hardly three-quarters of an inch to 

 pierce. Yet not one came out. On opening the logs I found 

 all my captives dead. A pinch of sawdust represented all 

 they had done. 



I had expected more from their sturdy mandibles. In 

 spite of their boring-tools the hermits died for lack of skill. I 



