14 THE INDUSTRIES OF ANIMALS. 



act by instinct, the latter reason their acts at each 

 step. 



Instinctive actions originate in reflective actions. — 

 No doubt it may be said : It is a pure hypothesis thus 

 to consider instinct as derived from intelligence ; why 

 not admit as well that instinctive acts have been such 

 from the beginning — in other words, that species have 

 been created such as we see them to-day ? The pre- 

 ceding explanation, however, has the advantage of 

 being in harmony with the general theory of evolution, 

 which, whether true or not, so well explains the most 

 complicated facts that for the present it must be 

 accepted. For the rest, if it is not possible to appraise 

 the psychic faculties possessed by the ancestors of 

 existing animals we may at least observe certain facts 

 which put us on the road of explanation. 



An interesting member of the Hymenoptera, the 

 Sphex, assures food for the early days of the life of its 

 larvae in a curious way.i Before laying its eggs it 

 seizes a cricket, paralyses it with two strokes of its 

 sting — one at the articulation of the head and the 

 neck, the other at the articulation of the first ring of 

 the thorax with the second — each stab traversing and 

 poisoning a nervous ganglion. The cricket is para- 

 lysed without being killed ; its flesh does not putrefy, 

 and yet it makes no movement. The Sphex places 

 an &'gg on this motionless prey, and the larva which 

 emerges from it devours the cricket. Here assuredly 

 is a marvellous and certain instinct. One cannot 

 even object that the strokes of the sting are inevit- 

 ably directed to these points because the chitinous 

 envelope of the victim offers too much resistance in 



^ "Elude sur I'lnstinct et les Metamorphoses des Sph^giens," 

 Ann. Sc. Nat., iv. Serie, t. 6, 1856. 



