ECOLOGY OF FLOWERS: POLLINATION 



173 



206. Protection of Pollen from Unwelcome Visitors It 



IS usually desirable for the flower to prevent the entrance 

 of small creeping insects, such as ants, which carry little 

 pollen and eat a relatively large amount of it. The means 

 adopted to secure this result are many and curious. In 

 some plants, as the common catchfly, there is a sticky 



Fig. 129. Bees visiting; Flowers, 



At the left, a bumblebee on the flower oi the dead nettle ; below, a similar 

 bee in the flower of the horse-chestnut; above, a honey-bee in the 

 flower of a violet. 



ring about the peduncle, some distance below the flowers, 

 and this forms an effectual' barrier against ants and like 

 insects. Very frequently the calyx tube is covered with 

 hairs, which are sometimes sticky. 



Sometimes the recurved petals or divisions of the corolla 

 stand in the way of creeping insects. In other cases the 

 throat of the corolla is much narrowed or closed by hairs 



