XI THE SCIENCE OF INSTINCT i6i 



equally. One of the three stabbed was kept in the 

 dark and foodless. In this case there was not only 

 darkness and want of food, but the serious wounds 

 inflicted by the Sphex, and yet for seventeen days it 

 perpetually moved its antennae. As long as this 

 kind of pendulum oscillates, the clock of life has not 

 stopped. On the eighteenth day the creature ceased 

 to wave its antennae and died. Thus the seriously 

 wounded insect lived in the same conditions as the 

 uninjured one four times as long. What seems as 

 if it should be a cause of death is really the cause 

 of life. 



However paradoxical it may at first appear, 

 this result is perfectly simple. Intact, the creature 

 agitates and spends itself; paralysed, it makes only 

 those feeble, internal movements, inseparable from 

 all organised life, and the waste of substance is in 

 proportion to the amount of action employed. In the 

 first case the animal machine works and spends 

 itself; in the second it is at rest and saves itself 

 up. Nourishment no longer repairing loss, the 

 insect in motion spends in four days its food reserves 

 and dies ; the motionless one does not spend them, 

 and lives eighteen. Physiology tells us that life is 

 continual destruction, and the Sphex's victims are a 

 most elegant demonstration of this fact. 



One more remark. Fresh food is absolutely 

 necessary to larvae of the Hymenopteron. If the 

 prey were stored intact, in four or five days it would 

 be a dead body, given up to decay, and the newly 

 hatched grubs would find no food but a corrupted 

 mass. Touched by the sting it can live two or 

 three weeks — a period more than sufficient for the 



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