CONSPICUOUS FLOWERS RARELY VISITED BY INSECTS 163 



of the bed Plateau introduced the cooked juice of cherries, and 

 in two umbels on the right side anisette was used. Immediately 

 many flies belonging to the families Muscidae and Sarcophagidae, 

 and later two Syrphidae and three wasps were attracted to the 

 odoriferous liquids. The clusters which remained in their natural 

 state are said not to have received a single visit. 



A large plant of Pelargonium zonale, of the variety called 

 " General Grant," produced in my garden during the larger part 

 of the summer of 1912 numerous bright scarlet umbels. The 

 nectaries had disappeared and the stamens were largely petaloid 

 so that the flowers yielded neither nectar nor pollen; notwith- 

 standing frequent inspections no insect visits were observed 

 during the larger part of the season. On September 23, at 1 :00 

 p. m., odorless sugar syrup was introduced into two umbels near 

 the center of the plant. From the 23rd to the 26th, no insects 

 found the syrup, which was renewed from time to time as it 

 evaporated. The 26th was warm and clear, and in the afternoon 

 I saw a honey-bee inspect a cluster of flowers near the ground, 

 but it did not alight. The weather continued fair on the 27th, 

 and at 7:00 a. m., there were no insects on the flowers; but at 

 9:00 o'clock there were, at least, a dozen honey-bees feeding on 

 the syrup, which was speedily consumed. There were six other 

 fully expanded umbels on which there was no syrup, and it was 

 interesting to note how the bees searched them again and again 

 in their efforts to find more of the edible liquid. Two other 

 umbels with a few buds partially open were also carefully exam- 

 ined. Their attention at first was entirely confined to the gaudy 

 flowers, but later they discovered some of the liquid, which had 

 dripped on a few leaves, and removed it. Their number continued 

 to increase so long as I supplied the syrup. Later they flew to a 

 bed of Portulaca grandiflora Lindl., to the inflorescence of which 

 they had never before been seen to pay any attention, and inspec- 

 ted flower after flower but seldom alighted. >» 



Evidently the bees had learned from past experience to asso- 

 ciate the presence of nectar with conspicuousness, and though 

 they had never found any food in these particular flowers, they 

 had no doubt continued to occasionally inspect them, as in the 



29 During a part of the time this experiment was in progress one of the colonies 

 in my apiary was allowed to remove the honey from a few partially filled combs; 

 and it subsequently occurred to me that this probably stimulated the bees to search 

 the flowers more diligently for nectar. 



