IV te ON PLANT LIFE 127 
less. In the other two the anthers or cells pro- 
ducing the pollen, which in most flowers form 
together a round knob or 
head at the top of the 
stamen, are separated by 
a long arm, which plays 
on the top of the stamen 
as on a hinge. Of these 
two arms one hangs down 
into the tube, closing the 
passage, while the other Fig. 9. 
lies under the arched upper lip. Wien 3 the 
Bee pushes its proboscis down the tube (Fig. 11) 
Fig. 10. ; Fig. 11. 
it presses the lower arm to one side, and the 
. upper arm consequently descends, tapping the 
