256 SOCIAL LIFE IN THE INSECT WORLD 



extremity to the opening of the passage, and the egg is 

 immediately lodged at the very bottom. 



Anatomy will give us the answer to the riddle, which 

 is otherwise indecipherable. I open the body of a gravid 

 female. There, before my eyes, is something that takes 

 my breath away. There, occupying the whole length of 

 the body, is an extraordinary device ; a red, horny, rigid 

 rod ; I had almost said a rostrum, so greatly does it 

 resemble the implement which the insect carries on his 

 head. It is a tube, fine as a horsehair, slightly enlarged 

 at the free extremity, like an old-fashioned blunderbuss, 

 and expanding to form an egg-shaped capsule at the 

 point of origin. 



This is the oviduct, and its dimensions are the same as 

 those of the rostrum. As far as the perforating beak 

 can plunge, so far the oviscapt, the interior rostrum, will 

 reach. When working upon her acorn the female 

 chooses the point of attack so that the two com- 

 plementary instruments can each of them reach the 

 desired point at the base of the acorn. 



The matter now explains itself. The work of drilling 

 completed, the gallery ready, the mother turns and places 

 the tip of the abdomen against the orifice. She extrudes 

 the internal mechanism, which easily passes through the 

 loose debris of the boring. No sign of the probe appears, 

 so quickly and discreetly does it work ; nor is any trace 

 of it to be seen when, the egg having been properly 

 deposited, the implement ascends and returns to the 

 abdomen. It is over, and the mother departs, and we 

 have not caught a glimpse of her internal mechanism. 



Was I not right to insist ? An apparently insignificant 

 fact has led to the authentic proof of a fact that the 



