44 



NORMAL AND EXPERIMENTAL POLLINATION. 



drop in such a position that its head was just above the drop. It first 

 walked around the filament column, then commenced to suck honey and 

 continued for 90 seconds, until the drop was two-thirds gone. While 

 sucking, it supported itself on a petal with the front and hind pairs of legs. 



Diluted honey was placed in drops at the base of the filaments. Halictus 

 pulzenus went from one nectary to the next, sucking nectar, as usual, and 

 did not notice the honej^. Bombus juxtus came and crowded Halictus 

 away, but did not stay long enough to secure all the honey. At the next 

 flower there was a drop at one point and it sucked at this until the honey 

 was all gone. This took a minute; it then walked around the flower and 

 dipped its ligule into each nectary. One individual stayed at a honey drop 

 for more than 3 minutes. After this it walked around the flower, back to 

 the honey-drop, and sipped more of it. The end of the ligule did not reach 

 the nectary, as the tip was visible in the honey, moving in all directions. 

 This bee flew to another flower that had a drop of honey in a similar position 

 and walked around the column of anthers without stopping for nectar. 



A circle of diluted honey was placed around the base of the filaments. 

 Bombus juxtus took a few sips of this, but did not stay long. Another 

 juxtus landed with its head pointed toward the outside of the flower and 

 sucked honey from a drop that had run half way down the petals. It then 

 went to the next flower which had honey in a similar position, took a sip, 

 and flew away. When Bombus bifarius came to a flower on which there 

 was diluted honey, it stayed and sipped, instead of trying to push the ligule 

 into the nectaries. However, it did not remain until all the honey was 

 gone, but flew to normal flowers and took nectar there. Halictus pulzenus 

 went to a flower with a honey-drop, but worked at all the nectaries without 

 finding it. 



Diluted honey wab put around the base of the stamens of 10 flowers, 

 which were placed beside 10 normal ones. The results of an hour's observa- 

 tion are shown in table 30. 



Table 30. — Visits to normal and honey flowers. 



While there were one-half as many visitors to the honey as to the normal 

 flowers, these averaged but one visit each in contrast to 6 each for the 

 normal. In addition, 7 bumble-bees inspected the honey flowers. The 

 effect of added honey in disturbing the normal response is well shown in the 

 case of Bombus bifarius. The honey flowers received nearly as many visitors 

 as the normal ones, but practically all of these made single visits, in contrast 

 to an average of 8 for the normal flowers. 



