PSYCHIC LIFE OF INSECTS BOUVIER. 457 



a fixed habit with Ammophila urnaria, it belongs only to certain in- 

 dividuals more highly endowed than others and is perhaps only 

 accidental even with them. Maybe it will finally pass into the in- 

 stinctive habits of the species; for the present it belongs to the 

 domain of individual intelligent acts. The crabs of the genus Melia 

 are already farther advanced, all the species carry anemones and all 

 exhibit a curious modification of the pincers, the fine teeth having 

 become elongated and needlelike so as to give them a better hold 

 on their guest and tool. That they are adapted to the latter is evi- 

 dent, yet this adaptation is not such that the crab is likely to be in 

 serious danger when it has not its Actinia. Many of the Melias 

 brought back by explorers are not provided with anemones, and we 

 may believe that the presence of this implement guest is not yet of 

 vital importance to the species of this peculiar genus. The case of 

 the ants which use their larvse as needles is quite different. With 

 them this singular habit is innate and specific. Though probably 

 acquired through intelligent acts, it now belongs entirely to the 

 domain of instinct in the species among which it prevails. And thus 

 we always come back to that predominating fact of the psychologi- 

 cal history of Articulates, namely, the transformation of intelligent 

 acts into instinctive acts. The following considerations formulated 

 by Bergson eminently apply to this group : 



Among animals, invention is never more than a variation on the theme of rou- 

 tine. Locked up as it is within the habits of its species, the animal succeeds 

 no doubt in broadening these by individual initiative ; but its escape from autom- 

 atism is momentary only, just long enough to create a new automatism ; the 

 gates of its prison close as soon as they are opened ; dragging the chain merely 

 lengthens it. Only with man does consciousness break the chain. 



Man occupies the topmost place in the scale of vertebrates, for, 

 breaking the bonds of instinct, he insures thereby the complete ex- 

 pansion of his intellect. Insects, especially Hymenoptera, hold the 

 same dominating position in the scale of Articulates, where they are 

 the highest achievement of instinctive life. These two groups repre- 

 sent the actual extremes of the two paths followed by psychic evolu- 

 tion in the Animal Kingdom; the articulates are going toward in- 

 stinct, the vertebrates toward intelligence. These two courses are 

 quite opposite, but why have they diverged? At the beginning of 

 their evolution, during that far distant epoch when they were dif- 

 ferentiating along four main lines (Echinoderms, Molluscs, Articu- 

 lates, and Vertebrates), animals were threatened by a great danger — 

 " an obstacle," says Bergson, " that doubtless almost checked the 

 progress of animal life. There is a peculiarity which we can not help 

 being struck by when we glance at the Paleozoic fauna. The mollusks 

 at that time were more universally provided with shells than those 

 of to-day. The arthropods in general were provided with a carapace. 



