116 SOUTH AFRICAN BOTANY 
only being receptive. They will receive pollen from any 
insect which has previously visited a younger flower. 
Finally, in many cases, the stigmas curl round to touch 
I-}-pertile anther lobe 
-connective 
Fia. 65.—Salvia Flower. Fg. 66.—Longitudinal S2ction 
of Flower of Salvia, Showing 
the Mechanism of the Sta- 
mens. 
their own styles and thus they become self-pollinated. 
Thus every floret is practically certain to set seed. The 
arrangement can be well seen in the Sunflower and in 
ry pollen . > - stigmas 
andrecium 
a b c 
Fie. 67.—Disc Florets of Helianthus (Magnified). 
a. First stage. 0b, Second stage. c. Third stage. 
the Cosmos (fig. 67). The Cornflower (Centaurea) 
is similar, except that, instead of the style lengthening, 
the stamens, when touched, contract, thus forcing the 
pollen out of the top of the anther tube. 
