Turner, Homing of Ants. 371 



were used. Pupae and ants were placed on the stage and the ants 

 allowed to find their way home. 

 These experiments fall into the following groups : 



1. Those in which the ants in passing home must pass ob- 

 liquely towards the source of lignt, then parallel to the rays but 

 away from the source. 



2. Those in which the ants must pass obliquely away from the 

 source, then parallel to the rays and towards the source. 



3. Those in which the ants must pass obliquely away from the 

 source and then at right angles to the rays. 



4. Those in which the ants must pass obliquely towards the 

 source of light and then at right angles to the rays. 



5. Those in which the path was practically equally illuminated 

 on all sides. 



6. Those in which the ants must pass obliquely towards the 

 source of light, then parallel with the rays and towards the source, 

 then at right angles to the rays, then parallel with the rays and 

 away from the source. 



7. Those in which the ants must pass obliquely away from 

 the source, then parallel with the rays and away from the source, 

 then at right angles to the rays, then parallel with the rays and 

 towards the source. 



In the sixth and seventh cases two inclines and two stages were 

 used. The stages were connected by an incline and one incline 

 led from stage number two to the ground. The pupre and ants 

 were placed on stage number one. 



All of the above experiments were performed with each of the 

 following species: Cremastogaster lineolata Say, Forelius mac- 

 cooki McC, Lasius niger L., Myrmica punctiventris Rog., Pheidole 

 sp. .f*, Prenolepis imparls Say, Tapinoma sessilis Say, Formica 

 pallide-fulva Latrl., Formica fusca var. subsericea Say, Dorymyr- 

 mex pyramicus Rog., Aphaenogaster lamellatus Mayr, Monomor- 

 ium minutum, Mayr. In most of these cases experiments were 

 performed with several different colonies of the same species. 



If ants are heliotropic in the sense of Loeb, they should move 

 from or to the light, in the direction of the rays, until the edge of 

 the stage is reached; then they should pass to the under (shaded) 

 side of the stage, or else remain on its margin until the direction 

 of the rays of light is changed. 



But under each of the seven conditions mentioned above, and 



