ANTS AND SOME OTHER INSECTS. 23 



So many bees were visiting the Dahlias that at times there 

 were two or three to a flower. 



Result : Immediately all the completely covered flowers ceased 

 to be visited by the bees. Dahlia (<r) continued to be visited like 

 those completely visible. The bees often flew to Dahlias () but at 

 once abandoned them ; a few, however, succeeded in finding the 

 disc beneath the leaves. 



Then as soon as I removed the covering from a red Dahlia the 

 bees at once flew to it ; and soon a poorly concealed specimen was 

 detected and visited. Later an inquisitive bee discovered the en- 

 trance to a covered Dahlia from the side or from below. Thence- 

 forth this bee, but only this one, returned to this same covered 

 flower. 



Nevertheless several bees seemed to be seeking the Dahlias 

 which had so suddenly disappeared. Towards 5.30 o'clock some 

 of them had detected the covered flowers. Thenceforth these in- 

 sects were rapidly imitated by the other bees, and in a short time 

 the hidden flowers were again being visited. As soon as a bee had 

 discovered my imposition and found the entrance to a hidden 

 flower, she flew in her subsequent journeys, without hesitation to 

 the concealed opening of the grape-leaf. As long as a bee had 

 merely made the discovery by herself, she remained unnoticed by 

 the others. When this was accomplished by several, however, (usu- 

 ally by four or five,) the others followed their example. 



Plateau, therefore, conducted his experiments in a faulty man- 

 ner and obtained erroneous results. The bees still saw the Dahlias 

 which he at first incompletely concealed. Then, by the time he 

 had covered them up completely, but only from above, they had 

 already detected the fraud and saw the Dahlias also from the side. 

 Plateau had failed to take into consideration the bee's memory and 

 attention. 



September i3th I made some crude imitations of Dahlias by 

 sticking the yellow heads of Hieracium (hawkweed) each in a Pe- 

 tunia flower, and placed them among the Dahlias. Neither the 

 Petunias nor the Hieracium had been visited by the bees. Never- 

 theless many of the honey and humble-bees flew at first to the arte- 



