IX ADVANCED THEORIES 123 



unriddle this new problem. In any case S. flavi- 

 pennis, either from imperious necessity, or from 

 motives unknown to me, sometimes replaces her 

 favourite prey, the grasshopper, by another, the 

 Acridian, altogether unlike outwardly to the former, 

 but still an Orthopteron. 



The observer on whose authority Lepeletier de 

 St. Fargeau speaks of this Sphex's habits witnessed 

 in Africa, near Oran, a similar storing of Acridians. 

 S. flavipennis was surprised by him dragging along 

 an Acridian. Was it an accidental case, like the 

 one seen by me on the banks of the Rhone ? 

 Was it the exception, or was it the rule ? Were 

 grasshoppers wanting around Oran, and did the 

 Hymenopteron replace them by Acridians ? Circum- 

 stances compel me to ask the question without 

 finding a reply. 



Here should be interpolated a certain passage 

 from Lacordaire's Introduction to Ento7nology} against 

 which I long to raise my voice in protest. Here 

 it is : " Darwin, who has written a book on purpose 

 to prove the identity of the intellectual principle 

 which produces action in man and animals, walking 

 one day in his garden noticed on the ground in a 

 shady walk a Sphex which had just caught a fly 

 nearly as big as itself. He saw it cut off with its 

 mandibles the victim's head and abdomen, keeping 

 only the thorax, to which the wings remained 

 attached. It then flew away, but a breath of wind 

 striking the fly's wings twirled the Sphex round, 



1 In a later essay, Fragments on Psychology, M. Fabre withdraws 

 these strictures on (Erasmus) Darwin, explaining that they are based 

 on a misquotation by Lacordaire, who writes " Sphex " where Darwin 

 had said ' ' wasp. " 



