62 



NORMAL AND EXPERIMENTAL POLLINATION. 



painted flowers, both went readily from these to the normal or the reverse, 

 the ratio for Apis being 27:67 and for Bombus 12:31, or almost identical 

 in value. The false flowers made of Campanula petals were treated like 

 the paper ones, Bombus visiting practically as many of them as the normal 

 and Apis merely inspecting them without landing. Honey received little 

 attention from either, the paper flowers with honey-drops being entirely 

 ignored. 



MERTENSIA PRATENSIS. 

 NORMAL POLLINATION. 

 Behavior. — The flowers are pendant and have a tubular corolla with 

 a bell-shaped expansion below (plate 11). The corolla-tube is only about 

 15 mm. long, but both Vespa germanica and Bombus juxtus often bore holes 

 at the base of the corolla and steal nectar. They land on the corolla-tube 

 with their hind legs toward the corolla mouth. Juxtus carries yellow pollen 

 on its legs, probably from Fragaria or Rubus strigosus previously visited, 

 but it does not gather pollen at Mertensia. It comes to this for nectar, 

 and upon landing it hangs on to the pendant corolla-tube, pushes out its 

 ligule, and at once takes nectar. Edwardsi enters the flower, resting on the 

 lower lobe of the corolla, and its head is pushed into the tube for the nectar. 

 While the stigma comes in contact with the abdomen and receives the 

 pollen found there, its head brushes against the dehiscing anthers and col- 

 lects pollen. Osmia pentstemonis is so eager for nectar that it opens buds 

 and pushes its head into the corolla-tube to secure it. Andrena madronitens 

 usually rifles flowers of nectar when a hole has already been made. Other- 

 wise, it pushes its head directly into the tube, bending at the thorax 

 so that the abdomen is outside the corolla-tube and pointing upward. 

 Halictus pulzenus lands at the corolla mouth, eats pollen, and then goes to 

 the base of the corolla to puncture it for nectar. Other species of Halictus 

 push far into the corolla tube, where they scrape pollen so vigorously with 

 the hind legs that it flies out of the opening. While doing this, the head 

 is very near the nectar, probably sipping it, and the hind legs are resting on 

 the anthers. Halictus (Evylaeus) sp. bends over the edge of the corolla -tube, 

 while its head is in contact with the stamens, and touches the stigma as it 

 leaves the flower. Dejeania vexatrix lands and rests its legs on the lower 

 edge of the petals, while it pushes its head into the corolla-tube and sucks 



Table 47. — Visitors to normal flowers. 



