The Glow- Worm and Other Beetles 



in the thickness of the wood, was a wide bur- 

 row with a very low ceiling, almost a slot; 

 to-day the passage is cylindrical: a gimlet 

 could not bore it more accurately. This sud- 

 den change in the system, of road-making on 

 behalf of the coming insect once more sug- 

 gests for our meditation the eminent degree 

 of foresight possessed by a bit of an intes- 

 tine. 



The cylindrical exit-way passes through 

 the strata of wood along the shortest line, 

 almost normally, after a slight bend which 

 connects the vertical with the horizontal, a 

 curve with a radius large enough to allow the 

 stiff Buprestis to tack about without diffi- 

 culty. It ends in a blind-alley, less than a 

 twelfth of an inch from the surface of the 

 wood. The eating away of the untouched 

 sheet of wood and of the bark is all the la- 

 bour that the grub leaves the insect to per- 

 form. Having made these preparations, 

 the larva withdraws, strengthening the 

 wooden screen, however, with a layer of fine 

 sawdust; it reaches the end of the round 

 gallery, which is prolonged by the completely 

 choked flat gallery; and here, scorning a spe- 

 cial chamber or any upholstery, it goes to 

 sleep for the nymphosis, with its head to- 

 wards the exit. 



214 



