The Modern Theory of Instinct 37 1 



hatched grub should be able to gnaw peacefully, 

 in its narrow cell, a live and comparatively 

 enormous prey. The suppression of all move- 

 ments in the victim is the only means of 

 realizing these conditions ; and this suppression, 

 to be complete, requires sundry dagger-thrusts, 

 one in each motor centre. If the paralysis and 

 the torpor be not sufficient, the Grey Worm 

 will defy the efforts of the huntress, will struggle 

 desperately on the road and will not reach the 

 journey's end ; if the immobility be not com- 

 plete, the %^^%, fixed at a given spot on the 

 worm, will perish under the contortions of the 

 giant. There is no ma media, no half-success. 

 Either the caterpillar is treated according to 

 rule and the Wasp's family is perpetuated ; or 

 else the victim is only partially paralysed and 

 the Wasp's offspring dies in the ^%'g. 



Yielding to the inexorable logic of things, 

 we will therefore admit that the first Hairy 

 Ammophila, after capturing a Grey Worm to 

 feed her larva, operated on the patient by the 

 exact method in use to-day. She seized the 

 creature by the skin of the neck, stabbed it 

 underneath, opposite each of the nerve-centres 

 and, if the monster threatened further resistance, 

 munched its brain. It must have happened 

 like this ; for, once more, an unskilled murderess, 

 doing her work in a perfunctory and haphazard 



