FURNISHING THE LARDER 



rests ; but it soon begins to take a curved direction, and 

 the top overhangs to a degree which looks extremely 

 perilous. The unstable appearance is enhanced by the 

 structure of the walls, for the tiny masses of moulded 

 sand of which they are built up are not fitted very closely 

 together indeed there are often very obvious crannies 

 and openings which suggest a tube of rude filigree work 

 rather than a turret of solid masonry. It is evident 

 enough that such a slight edifice is not meant to endure ; 

 but what, in that case, can be the use of it? And why 

 should the wasp trouble to build it at all ? The pit we can 

 understand; that is going to be a nest wherein the egg 

 will be deposited; but the purpose of the outwork is not 

 at first sight so clear. Reaumur, who watched these 

 insects working both long and patiently, discovered one 

 possible use of the structure when he observed an ichneu- 

 mon-fly that tireless and terrible enemy of other insects 

 peer into the top of the tower and then retreat, apparently 

 discouraged in his felonious intentions by the depth of 

 the dark tunnel by which he was confronted. The outwork, 

 then, is of service in keeping out malevolent intruders 

 while the cell is being dug and provisioned; but that is 

 only a secondary object, and conjecture failing us, we are 

 enlightened as to its true use by carefully observing the 

 proceedings of the Odynerus herself. Having sunk a 

 shaft to the depth of several inches deep enough, that 

 is, for the extremity to be beyond the undue influence of 

 extremes of heat or cold the wasp goes a-hunting for live 

 caterpillars, with ten or twelve of which, closely packed, 

 she furnishes her larder. With them she places an egg, and 

 then nothing further remains to be done except to fill in 

 the upper part of the hole in order to make all snug for 

 the future grub. It is at this stage in the series of 

 K 149 



