Scientific Work of Dr. C. H. Turner 11 



some of the big problems of animal behavior. For in- 

 stance, he discovered, by ingenious experiments, that 

 ants are not guided home by odors, but that light-rays 

 as landmarks are a larger factor than has heretofore 

 been supposed in their orientation. Again, by adjusting 

 the window shades on three windows in the room where 

 mud-daubers were nesting, thereby alternating the light 

 and darkness. Dr. Turner proved that wasps find their 

 way home, not by some mysterious sense, but by means 

 of landmarks. 



In his work on the homing of the burrowing bees, he 

 devoted from five to ten hours a day during the 

 month of August to studying the insects in the field. He 

 found that any change made in the topography is sure to 

 confuse the insect upon its return, in finding the entrance 

 to its home. Many other details were brought to light 

 which militate against the old idea of a "homing in- 

 stinct" and against Bethe's contention that bees are 

 guided home by an unknown force which acts reflexly. 

 He concludes from his work that the burrowing bees are 

 guided by memory in finding the way home, and that they 

 examine carefully the neighborhood of the nest for the 

 purpose of forming memory pictures of the topographi- 

 cal environment of the burrow. 



Whether insects can or cannot distinguish colors is a 

 matter of much theoretical importance, for the correct 

 interpretation of the relation of insects to flowers de- 

 pends upon this answer. Most students of natural selec- 

 tion believed at one time that forms and colors of flowers 

 were adaptations to attract insect visitors. Dr. Turner 

 solved this problem in 1910 by experiments carried on 

 in 'Fallon Park. By his ever ingenious methods he 

 contrived tests with certain colored disks of paper and 

 certain colored boxes which were filled with honey. After 



