246 SOCIAL LIFE IN THE INSECT WORLD 



perforated : that is to say, those in which the perforation 

 is not yet surrounded by the brown ring which appears 

 in course of time. Let us shell them. Many contain 

 nothing out of the way ; the Balaninus has bored them 

 but has not laid her eggs in them. They resemble the 

 acorns which for hours and hours were drilled in my 

 laboratory but not utilised. Many, on the contrary, 

 contain an egg. 



Now however distant the entrance of the bore may be, 

 this egg is always at the bottom of the acorn, within the 

 cup, at the base of the cotyledonary matter. The cup 

 furnishes a thin film like swan-skin which imbibes the 

 sapid exudations from the stem, the source of nourish- 

 ment. I have seen a young grub, hatched under my 

 eyes, eat as his first mouthfuls this tender cottony 

 layer, which is moist and flavoured with tannin. 



Such nutriment, juicy and easy of digestion, like all 

 nascent organic matter, is only found in this particular 

 spot ; and it is only there, between the cup and the base 

 of the cotyledons, that the elephant-beetle establishes her 

 egg. The insect knows to a nicety the position of the 

 portions best adapted to the feeble stomach of the newly 

 hatched larva. 



Above this is the tougher nutriment of the cotyledons. 

 Refreshed by its first meal, the grub proceeds to attack 

 this ; not directly, but in the tunnel bored by the 

 mother, which is littered with tiny crumbs and half- 

 masticated shavings. With this light mealy diet the 

 strength of the grub increases, and it then plunges 

 directly into the substance of the acorn. 



These data explain the tactics of the gravid mother. 

 What is her object when, before proceeding to sink her 



