ECOLOGY OF FLOWERS; POLLINATION 177 
In some flowers whose stamens perform rapid move- 
ments when an insect enters, it is easy to see how directly 
useful the motion of the stamens is in securing cross- 
pollination. The stamens of the laurel, Halmia, throw 
little masses of pollen, with a quick jerk, against the body 
of the visiting insect. Barberry stamens spring up against 
the visitor and dust him with pollen. The common gar- 
den sage matures its anthers earlier than its stigmas. In 
Fig. 132, 4 the young flower is seen visited by a bee, and 
one anther is shown pressed 
closely against the side of 
the bee’s abdomen. The 
stigma st is hidden within 
Fic. 133. Flower and Stamens of Common Sage. 
A, p, stigma; a, anther; B, the two stamens in ordinary position; J, fila- 
ment; m, connective (joining anther-cells); a’, anther-cells; C’, the 
anthers and connectives bent into a horizontal position by an insect 
pushing against a. 
the upper lip of the corolla. In B, an older flower, the 
anthers have withered and the stigma is now lowered so 
as to brush against the body of any bee which may enter. 
A little study of Fig. 183 will make clear the way in 
which the anthers are hinged, so that a bee striking the 
empty or barren anther-lobes, a, knocks the pollen-bearing 
lobes, a’, into a horizontal position, so that they will lie 
closely pressed against either side of its abdomen. 
