306 



EXPERIMENTS WITH PLANTS 



showing the anther (an} with a bee entering and about 

 to strike his head against the lower part of the anther - 



stalk. The stalk of the 

 anther turns on a hinge 

 or pivot, so that, when 

 the lower part is struck, 

 down flops the anther 

 and discharges pollen 

 all over the bee (Fig. 

 169, B). In the mean- 

 time the stigma (st) is 

 up out of the way, but 

 when the pollen is all 

 discharged it grows 

 down and takes the po- 

 sition shown in Fig. 169, 

 C. When a bee en- 

 ters such a flower the 

 pollen is transferred di- 

 rectly to the stigma. 



There are numerous 

 other devices for loading the insect with pollen, in- 

 cluding the pumping mechanism of the Pea flower, the 

 irritable stamens of Barberry, Prickly Pear, etc., 

 which spring when touched at the base, thereby scat- 

 tering pollen on the insect, and also the curious 

 arrangements found in Orchids. An account of these, 

 together with other matters concerning pollination, will 



169. Sage flowers cut open: a, a bee entering 

 the flower; 6, an anther (an) striking the 

 bee; c, the stigma (st) of an older flower 

 removing pollen from the bee. 



