592 PSYCHICAL FACULTIES OF ANTS AND OTHER INSECTS. 



In a dahlia bed much frequented by bees and comprising about 43 

 crowns of various colors 1 covered with vine leaves certain of the 

 crowns as follows: 



(a) First, 17 and afterwards a total of 28 were completely covered 

 by bending the leaves about them and fastening them with pins. 



(b) In 4 only the yellow heart was covered. 



(c) In 1 this was reversed, the outer colored rays l)eing covered 

 and the heart left free. 



So many bees visited the dahlias that tlu're were often several on 

 the same crown. 



Result. — The bees immediately ceased to visit the completely cov- 

 ered crowns. Dahlia c was soon revisited like those that had been 

 left uncovered. Bees often flew to the h dahlias but immediately left 

 them. A few, however, succeeded in getting under the leaves and 

 reaching the hearts. 



As I removed the covering of a red dahlia the bees at once flew back 

 to it. Soon a badly covered dahlia was discovered and revisited by 

 them. Later an exploring bee discovered how to reach a covered 

 dahlia either below or from the side. From that time on these bees, 

 and onl\" these, came back to those covered dahlias. 



Yet various bees were a])parently searching for the vanished dahlias. 

 About 5.30 p. m. a few had discovered the covered crowns. From 

 this time on they were quickly imitated by the others, and in a short 

 time the covered crowns were freelj'' visited. When a bee discovered 

 my device and the entrance to the covered crown he in his succeeding 

 journeys flew without delay to the lower concealed entrance of the 

 vine leaf. As long as one bee alone had found the (entrance he was 

 not regarded by the others, but if there were several (usually 4 or 

 5 at least) they were followed by the others. 



Plateau's experiment therefore was a bad one and led to false con- 

 clusions. The incompletely covered dahlias were still seen hy the 

 bees. When he completely covered them from above the bees were 

 already aware of his trick and still saw the dahlias from the side. 

 Plateau had not reckoned on the memory" and watchfulness of the bees. 



On September 13 1 made some rude imitations of dahlias by stick- 

 ing yellow heads of hieracium into petunia flowers and placed these 

 under the dahlias. Neither the petunias nor the hieracium were visited 

 b}^ the bees; yet many bees and bumble bees flew at tirst to my arti- 

 facts, quite as many as to the dahlias. They left them immediately, 

 however, apparently noting the error l)y the smell. The same occurred 

 with a dahlia whose heart had been replaced by the heart of a hier- 

 acium. 



As a counter experiment I placed a fine fragrant dahlia heart among 

 the w^hite and yellow chrysanthemums neglected by the bees and situ- 

 ated at the border of the dahlia bed. For half an hour all the bees 



