53 8 ANTS. 



;md up the incline, but to B this was an insoluble problem. It con- 

 tinued for a long time to move at random over the stage, reaching down 

 o\vr first one edgr and then over another, as though it were reaching 

 for a support that wa- not to be found; but nothing prompted it to 

 pass down the incline. In experiments where the time required to 

 learn the trick was not the point to be investigated, I had sometimes 

 helped ants to learn the way by forcing them with forceps or spatula 

 to move in the right direction. I thought I would thus help B to learn. 

 Si i with my forceps I pushed it along. Several times I succeeded in 

 getting it to the incline, but nothing that I did would induce it to go 

 down. I had failed, but this was not the first time I had failed in 

 ^imilar attempts with other ants. 



' Prompted by another thought, I shoved the section-lifter under 

 the ant and transferred it to the island. The ant then stepped off and 

 carried the pupa into the nest. As soon as B returned to the island, I 

 shoved the section-lifter under it and transferred it to the stage. B 

 stepped off and picked up another pupa. With the section-lifter I 

 again transferred it to the island. After this had been repeated several 

 times, the moment I presented the section-lifter, whether on the island 

 or on the stage, the ant immediately mounted it and rested quietly 

 thereon until it had been removed to the stage or to the island ; then 

 it stepped off and picked up a pupa or else went into the nest. I 

 usually held the section-lifter from two to four millimeters above the 

 surface of the island or stage. In this manner the industrious creature 

 passed to and from the stage about fifty times in something less than 

 two hours. 



' \Yhenever I presented the section-lifter to other ants of the same 

 colony they would attack it or avoid it, or else mount it and roam 

 over blade and handle and sometimes even my hand. When the same 

 section-lifter was presented to A (the one that all this time had been 

 carrying pupae down the incline ) it would avoid it and pass on. 



' Thus I had two individuals of the same colony, at the same time 

 and under identical external conditions, responding to the same stimulus 

 in quite different ways. To the one the incline had no psychic value, 

 to the other it was a stimulus to pass to and from the stage. To the 

 one the section-lifter was a repellent stimulus, to the other an attractive 

 stimulus. Each had acquired a different way of accomplishing the 

 same purpose and each had retained and utilized what it had gained 

 by experience." 



While the foregoing considerations leave little doubt that ants have 

 memory, in the general sense of the word, it is, for obvious reasons, 

 no easy matter to form a satisfactory conception of the psychic proc- 



