SENSITIVE PLANTS 



arranged in pairs at the base of the petals in 

 each flower ; but not a single beetle reached 

 those honey glands without causing some of 

 the stamens to spring forward suddenly in the 

 manner previously described. Beetles that were 

 resting on the tops and the edges of the 

 ovaries were being continually thrown into the 

 centre of the flowers by the sudden jerk of 

 the closing stamens when touched by another 

 insect below, which had already reached the 

 nectar. And there the dislodged insect would lie 

 on its back struggling to regain its feet until its 

 exertions, together with the movements of other 

 agitated beetles, had brought forward every stamen 

 in the flower. Some of the beetles were gripped 

 between the heads of the stamens and the side of the 

 ovary and held there until they could wriggle out 

 of the clutch. 



How tightly the stamens can grip an insect 

 I have shown in Fig. 55 (Plate ^6) where I have 

 left the pin used to bring the sensitive stamens 

 into action within the grip of two of them — 

 another interesting experiment that may easily 

 be performed with a little care. 



The stamens open to shed their pollen by 

 means of a kind of valve at the top, and with 

 the sudden jerk forward the pollen is showered 

 out at the valve, and falls in all directions amongst 

 the struggling beetles within the flower ; and there- 

 in hes the secret of the whole matter. Those 

 black beetles, after being so roughly treated by 

 the stamens, became yellow beetles, since to 



