The PVisdom of Instinct 157 



nor antennae ; a spot absolutely stationary, 

 devoid of so much as a surface tremor. It is 

 in perfect safety, on the sole condition that the 

 Ephippiger cannot shift her position, turn over, 

 get upon her feet ; and this one condition is 

 admirably fulfilled. 



But, with several heads of game, all in the 

 same stage of paralysis, the larva's danger 

 would be great. Though it would have no- 

 thing to fear from the insect first attacked, 

 because of its position out of the reach of its 

 victim, it would have every occasion to dread 

 the proximity of the others, which, stretching 

 their legs at random, might strike it and rip 

 it open with their spurs. This is perhaps the 

 reason why the Yellow-winged Sphex, who 

 heaps up three or four Crickets in the same 

 cell, practically annihilates all movement in 

 its victims, whereas the Languedocian Sphex, 

 victualling each burrow with a single piece of 

 game, leaves her Ephippigers the best part of 

 their power of motion and contents herself with 

 making it impossible for them to change their 

 position or stand upon their legs. She may 

 thus, though I cannot say so positively, econo- 

 mize her dagger-thrusts. 



While the only half-paralysed Ephippiger 

 cannot imperil the larva, fixed on a part of the 

 body where resistance is impossible, the case is 



