Turner, Homing of Ants. 397 



of the incline and returned to the stage up the bottle by which the 

 stage was supported at its center. This it did until half the pupas 

 had been conveyed to the nest. 



4. On several different occasions, where I had attached a 

 second incline to a stage from which ants had been conveying 

 pupae down another incline to the nest, I have noticed that an ant 

 would occasionally ascend to the stage by the second incline, pick 

 up a pupa and then pass down the other inchne to the nest. 



5. During the first part of my experiments I was not looking 

 for data along this line, but towards the close I devoted five hours 

 an evening for two weeks to an investigation of the problem. For- 

 mica fusca var. subsericea served as a subject. I placed a number 

 of pupae and a marked worker on a stage from which an incline 

 led to the island. I found that in each case the ant had to learn 

 the way, not only from the pupae to the incline and down it to the 

 island and thence to the nest, but that it had also to learn the way 

 from the nest to and up the incline. And it usually took a much 

 longer time to learn the way from the nest to the stage than it did 

 to learn the way from the stage to the nest. Now if Pie Ron's 

 hypothesis were true, the muscular memory of the ant should 

 have carried it back to the stage in practically the same path by 

 which it had passed from the stage to the nest. But such was not 

 the case. On leaving the nest, the ant would wander first in one 

 direction and then in another, often returning to the nest. It 

 acted as though hunting for something it could not find. At times 

 it would fail entirely to find its way back. 



6. In my experiments on the role light plays in the home-going 

 of ants, I gathered some data on this point. With the light in a 

 certain position, the marked ant was allowed to learn thoroughly 

 the way to and from the stage to the nest. Then the light was 

 placed on the opposite side of the stage. The ant was always 

 much disturbed by the change and it always took it a long time to 

 find the way to the nest. But, having reached the nest, if Pieron's 

 hypothesis be correct, its muscular memory should have guided it 

 immediately back along the path by which it reached the nest. 

 The ant, however, always had a hard time finding the way back 

 to the stage and often it failed completely. 



Experiments with Odors. — Having observed that ants can find 

 their way about without eyes and without antennae, Pieron con- 

 cludes that odors play no part in the home-going of ants; but, as 



