52 



NORMAL AND EXPERIMENTAL POLLINATION. 



though blue led with 29 visits, followed by green 23, red 20, white and yellow 

 16 each. Oddly enough, white and yellow were the only colors sought by 

 the other species, but the numbers are too small to be significant. The 

 behavior of one Bombus juxtus was noted as it worked from flower to flower 

 and the following course was observed: blue, normal, hovered over green, 

 normal; next stalk, blue; third stalk, blue, normal, blue, normal. 



ADDITION OF NECTAR AND ODOR. 



Honey. — When a drop of honey was placed at the opening to the nectary 

 in a group of normal flowers, Apis mellifica found it at once and stayed at 

 the flower 6 minutes. In another experiment, honey was placed on every 

 flower on one plant, but the number of visitors was no more numerous than 

 to the normal plants adjoining. The bees merely happened to visit it and 

 were not especially attracted by the honey. However, when Bombus 

 juxtus did find the latter, it stayed at the drop until this was consumed. 

 When the drop of honey was put on the style branches, Bombus sucked 

 it up as readily as when it was over the openings to the nectaries. 



Odor. — Flower perfumes were put on cotton-wads and these then 

 wound around the several pedicels under the calyx. The groups of flowers 

 on which the different odors were placed were arranged with respect to the 

 direction of the wind so as to make the odor in each case as distinctive as 

 possible. Twelve flowers of each odor were used in addition to 24 normal 

 ones. The two sets of observations were made during succeeding hours on 

 August 9. 



Table 39. — Visitors and visits to perfumed flowers. 



The flowers with carnation were shaded more than those with violet in 

 the first part of the experiment, which probably accounts for the few visits. 

 During the next hour of observation, carnation was in a different location 

 and many more visitors came to it. The number of visitors per flower was 

 practically the same for normal and for perfumed stalks, but these averaged 

 only 4 visits each to the perfumed flowers in contrast to 8 each for the 

 normal ones, indicating again something of the usual disturbance caused 

 by strange odors. 



