414 WILLIAM M. MANN 



so as to leave no possibility of guidance by scent or the sight of 

 immediate objects. The sight of this ant is poor so that objects 

 at a considerable distance from the ant could have had no effect, 

 so the experiments agree with those of Cornetz and other 

 workers in showing the constancy of conservation of orienta- 

 tion. Santschi explains this by assuming that on the outward- 

 going trail certain rays of light (probably ultra-violet) make 

 an impression on the pigment of the ant's eye. Owing to the 

 structure of this organ these impressions are unequal in various 

 parts and are retained, making a sort of compass to orient the 

 ant on its return. By means of a mirror, Santschi changed the 

 direction of the light rays on homeward bound ants. Under 

 this influence the ant changed its course, but orientated itself 

 toward the nest when the mirror was taken away. Santschi 

 considers the "homing" sense a very complicated phenomenon, 

 involving many factors; but above all, the perception of these 

 physical rays, visible or not to us, is valuable as a basis for 

 orientation. 



Tanquary (39), in order to determine whether they would be 

 adopted, placed queens of Aphaenogaster tennesseensis with col- 

 onies of A. fulva, A. fulva aquia, A. fulva aquia var. picea. In 

 all cases the queen was eventually killed by the workers of the 

 other species, but a tendency toward adoption was shown by 

 the fact that the queen was often licked by the workers. A 

 queen of A. tennesseensis was placed with pupae of A. aquia. 

 She paid no attention to these. Some hatched, and at first 

 the queen remained by herself, but afterwards stayed with 

 them, and was readily adopted, as in the cases recorded by 

 Miss Fielde (Artificial Mixed Nests of Ants). 



Queens of Formica rufa subsp. obscuriventris were placed with 

 colonies of Formica fusca subsericea. Where the colony was 

 large, the queen was killed; when small, after being attacked 

 for a time, she was finally adopted. The queens showed decid- 

 edly inquilinous habits, and this, with the fact of their being 

 adopted by small colonies, with the previous finding of a mixed 

 colony in nature, shows that F. obscuriventris is, at least occa- 

 sionally, a temporary social parasite in the nests of F. subsericea. 



Experiments were made with 79 queens of Lasius (Acantho- 

 myops) latipes, introducing them into different colonies of other 



