42 Trans. Acad. Sci. of St. Louis 



body nor the direction of flight bore any constant rela- 

 tion either to the direction of the wind or the rays of the 

 sun. It would be erroneous to claim that these wasps 

 and bees find their way home by the method of "trial 

 and error," for there is no gradual "stamping in" of the 

 appropriate response. When the returning insect finds 

 the environment markedly changed, it searches until the 

 opening to its nest is found. On its next departure a 

 careful examination of the vicinity of the nest is made. 

 On its next return, unless the environment has been 

 changed in the meanwhile, the wasp or bee flies directly 

 to its burrow in the minimum amount of time ; there is 

 none of that blundering into solution which the method 

 of "trial and error" demands. 



The contention that wasps and bees use landmarks to 

 guide them home predicates to them the ability to recog- 

 nize things by sight. This predication is justified by the 

 following experiments which demonstrate that these in- 

 sects possess both color-vision and pattern-vision. 



A large number of cardboard artifacts were made." 

 Some were circular discs, some pill-boxes and others cor- 

 nucopias. Each cornucopia had a semi-circular flange 

 projecting beyond its mouth. The bottom of the outer 

 case of each pill-box projected a short distance beyond 

 the front, and the drawer of each box was shorter than 

 the case and contained an opening in its front end. 

 Some of these artifacts were colored red, some 

 blue, some marked with alternating red and green longi- 

 tudinal stripes, some with alternating red and green 

 transverse stripes; some marked with alternating black 



and white longitudinal stripes, some with alternating 



i"* Turner, C. H. Experiments on Color-Vision of the Honey Bee. 

 Biol. Bull., vol. 19. 257-279. 



Experiments on the Pattern Vision of the Honey 



Bee. Biol. Bull., vol. 21, pp. 249-264. 



