MARC HAL ON CERCERIS ORNATA. 203 



victim and then licks off the juice that exudes. All the bees 

 that have undergone this operation have the neck cut, some on 

 the median line, some on both sides. The supposition that Ger- 

 ceris proceeds differently with the bees which are destined to 

 feed the larvae, perhaps not malaxing them at all, or only deli- 

 cately, proves to be incorrect, since half the bees that were 

 taken from nests showed marks of being cut. The other half, 

 upon which no sign of a wound was visible, had probably re- 

 ceived lesions which resulted in death after a brief delay. Of 

 five bees taken from nests where the egg had not yet hatched 

 three days), only one responded to stimulation of the electric 

 three days), only one responded to stimulation of the electric 

 current by flexing the anterior legs at the moment that it was 

 applied, the others giving no reaction. Moreover of three 

 taken from a nest not yet fully provisioned one gave no response 

 to the electric current. 



These facts show that the instinct of the Sphecidae may well 

 have been derived from the struggle for existence. If Cerceris 

 paralyzes Halyctus it is partly in her personal interest, that she 

 may perform the malaxation at her ease. Does not the instinct 

 of all these wasps to paralyze their prey for the benefit of beings 

 which they do not know, since they are still in the egg, — which 

 they can never know, since they will die before the young hatch 

 out; which, by a series of well ordered acts assures the propa- 

 gation of the race without the insect having the least knowl- 

 edge of the aim to be reached; does not this instinct appear bet- 

 ter than any other so to unite all the conditions that it will 

 serve for an argument of the partisans of the supernatural in 

 l^ature? and yet we see that in the actual case the instinct can 

 be brought back to the most natural thing in the world — indi- 

 vidual interest and preservation of the individual. It may be 

 that other original causes have presided over the evolution of 

 the instincts of the solitary wasps, but while we wait for new 

 facts, to suppose such causes would be to make a useless hypoth- 

 -esis. 



