NATURAL HISTORY STUDIES 



wonderful manifestation of instinct requires no ap- 

 prenticeship, it is perfect from the first, it expresses 

 an irresistible inborn impulsion, at once untaught and 

 unteachable. The insect's achievements are due to 

 " inborn inspirations." They look like intelligence ; 

 but disturb the routine, and the difference becomes 

 at once apparent. To instinct everything within 

 the routine is easy ; but the least step outside is 

 difficult. 



It is many years since Fabre described the be- 

 haviour of the Sphex wasp in stocking a larder for 

 its young. It makes burrows, each consisting of a 

 horizontal porch, a sloping main shaft, and off 

 this three or four horizontal cells. In each cell 

 the wasp places an egg and three or four paralysed 

 crickets or related insects. Each cell is closed when 

 it is filled, and the shaft is closed when the storing 

 is completed. Another shaft is then sunk. 



When the Sphex catches its cricket it stings it, 

 usually three times, in three different strategic 

 points in the nervous system, the result being that 

 the cricket is incapable of movement, but remains 

 alive until the larvae of the Sphex are ready to devour 

 it. When the Sphex has stung the cricket, it grips 

 it by an antenna and drags it or flies with it to the 

 mouth of the burrow. There it lays it down, 

 and proceeds to inspect the burrow to see that 

 everything is as it should be. If everything is in 

 order, it comes up again, and drags the cricket 

 with it, going in backwards. The interesting 

 experiment that Fabre made was to remove the 

 cricket while the Sphex was making its inspection 



116 



