THE FLOWER AND THE BEE 



flies, the most common being the speedwells, tender little herbs 

 of the genus Veronica, which grow in our gardens, lawns, and 

 meadows. When June is a wet month the thyme-leaved speed- 

 well {Veronica serpyllifolia) is abundant. The white or pale- 

 blue petals are marked with deeper purple lines leading to the 

 nectar; the corolla-tube is yellow and the throat is fringed with 



Fig. 84. Speedwell. Veronica Chamoedrys 



A syrphid-fly flower. A, flower seen from the front; B, the same with the stamens placed 

 together; C, the same with a syrphid fly sucking nectar. (After Mueller) 



hairs to exclude water. (Fig. 84.) There are only two sta- 

 mens, one on each side of the flower, and a single pistil in the 

 centre, all three of which taper at the base so that they bend 

 easily. When a syrphid fly visits one of these flowers, the 

 stigma rests against the under-side of its body while the feet 

 grasp the stamens and draw them also beneath it, where they 

 leave a part of the pollen. Self-polhnation may be prevented 

 in some species by the stigma maturing before the anthers, but 

 in the thyme-leaved speedwell the anthers may deposit pollen 

 directly on the stigma. 



The syrphid flies are very common visitors to golden-yellow 

 flowers, like the buttercup and marsh-marigold, and Mueller, 

 observing that they often poised before them a few seconds be- 



172 



