58 NORMAL AND EXPERIMENTAL POLLINATION. 



that they were hard to find after these had opened, and this similarity 

 doubtless explains the attraction of more visitors to them. After the normal 

 flowers opened, those with artificial corollas were practically deserted, as 

 the following calendar shows. Visits to normal flowers are indicated by 

 the numeral alone. 



SUMMARY. 



In spite of the numerous visits to the normal flowers, but one crepe flower 

 received a visit after the normal ones opened. Not a single one of the paired 

 Geranium or Chamaenerium flowers was visited, though 19 Mentzelia flowers 

 of such pairs were. Bombus bifarius was the only species to inspect the 

 artificial or competing flowers, Apis not even visiting Mentzelia when 

 paired with these. This experiment also included false flowers made by 

 pasting petals of Geranium or Chamaenerium over those of Mentzelia, but 

 as these were noticed only by one bifarius, which stopped at a false Chamae- 

 nerium, they were not included in calendar or table. 



FRASERA SPECIOSA. 

 NORMAL POLLINATION. 

 Habit and structure. — The plants are 3 to 4 feet tall and wand-like, 

 growing on sunny slopes or in open woods. The flowers form a close 

 cluster often 2 feet long, but the number of those open at any one time is not 

 large and they must be sought throughout the inflorescence. When the 

 flower opens, the petals are curved so that the corolla is cup-shaped, but 

 as the anthers mature, they are flattened. At first, the filaments are 

 vertical or bend outward slightly, but they diverge as the anthers shed 

 singly or by pairs ; Two rows of hairs on a tongue-like projection extend 

 over the nectaries and protect them (plate 10). 



Behavior. — Bombus juxtus lands on the petals with its head pointing 

 toward the pistil. Its ligule is pushed under the hairs above the nectary, 

 and it sips in turn from each. In doing this the anther which extends 

 between the two petals touches the side of its abdomen. Occasionally this 

 bee stands with the abdomen over the style and its head pointing toward 

 the outside of the flower. When the anthers are about through dehiscing, 

 the petals close up, the corolla becomes cup-shaped again, and the stamens 

 project between the closed petals. Nectar is still being produced, and in 

 order to get it B. juxtus walks up the outside of the petals and dips its head 

 into the inside of the cup. In doing this, the side of the abdomen and head, 

 which have collected pollen from the dehiscing anthers, rubs pollen against 

 the now receptive stigmas. Halictus pulzenus walks over the pistils, then 

 up the filaments, and with its front legs and head collects pollen from the 

 individual anthers. Clisodon terminalis also comes to this flower for pollen 

 rather than nectar. It stands on its hind legs and collects with the front 

 legs and head. Apis mellifica lands in such a manner as to reach and empty 

 the nectaries in rapid succession. In one case a honey-bee took hold of the 

 dehiscing anthers with the front legs, and, while suspended, opened each 

 one, scraping out the pollen and placing it on the hind legs. 



Fifty flowers were under observation on the three days recorded in 

 table 44. 



