Turner, Homing of Ants. 383 



or where I had added to their pupae the pupae of some other colony 

 or species. In the latter case the alien pupae were sometimes car- 

 ried in and sometimes not. After the pupae had all been removed, 

 the ants would explore thoroughly both the stage and the incline. 

 In some of these cases, after they had learned the way down one 

 incline, I would add to the stage two or more inclines. In this 

 case, when the pupae had been removed, although no pupae had 

 been carried down these additional inclines, yet they would usually 

 be thoroughly explored by the ants. After the exploration had 

 been completed the ants gradually withdrew from the stage. It 

 may not be out of place to state that if any of the ants originally 

 placed on the stage failed to find their way home, they were carried 

 there by the others. 



After the workers had quieted down in the nest, the experiment 

 was repeated; it was repeated not only once but over and over 

 again, the series of experiments on the same colony often extend- 

 ing through several days. In the second experiment, in each of 

 the several dozen series tried, the first ant usually reached the nest 

 with a pupa in a much shorter time than did the first ant in the 

 initial experiment of the series (Figs, i, 3, 6), 



In some experiments there was not much difference in the time 

 of the two cases (Fig. 2) and in a few rare cases the time in the 

 second case w^as even greater than at first (Fig. 4). 



Frequently, in the midst of a series, the ants would act as though 

 they had forgotten the way and had to relearn it (Fig. 5). This 

 usually required much less time than at first. If any complications 

 were introduced in the midst of a series the ants were sure to be 

 delayed until they had mastered the situation (Figs. 3,6). Some- 

 times they would fail. All of these points are brought out in Figs. 

 I to 6, where the abscissas represent the number of each experiment 

 in the series, and the ordinates the time in minutes that elapsed 

 from the beginning of the series until the first pupa was carried 

 into the nest. No one could watch the random movements made 

 by the ants when first placed on the stage without being convinced 

 that the finding of the nest the first time was merely a matter of 

 chance; indeed, they sometimes failed completely to find it. The 

 slow and exploring gait with which most species make the first 

 few trips of the initial experiment of any series, when contrasted 

 with the rapidity of the later movements, indicates that the ants 

 learn the way home. The short period of time usually required 



