THE FLOWER AND INSECT-POLLINATION 163 



way, first the receptive stigma and afterward the shedding 

 pollen sacs occupy the same position. A visiting insect will 

 probably find flowers in both conditions, and in striking 

 against protruding pollen sacs in some flowers and protruding 

 stigmas in others, it carries pollen from one flower to another. 

 In this case, the stigma is ready first ; but it is more common 

 for the pollen to be ready first, as in wild geraniums, willow 

 herb (" fire weed "), etc. In the latter case, when the flower 

 opens, the eight shedding stamens project prominently, 

 while the style is sharply curved downward and backward, 



FIG. 130. Flower of willow herb (Epilobiuni) : A, anthers in position for shedding and 

 style curved downward ; B, later condition, with anthers empty and stigmatic 

 lobes of style in position for receiving pollen. After GRAY. 



carrying the stigmatic surface well out of the way (Fig. 130). 

 Later, the stamens bend away and the style straightens up and 

 exposes the stigma. The result of insect visits is the same 

 as described for the figwort. 



Still another arrangement is not very common, but none 

 the less interesting. The stamens and pistils are together 

 in the flower, but there are usually two forms of flowers. In 

 the little plant called " innocents " or " bluets," for example 

 (Fig. 131), one kind of flower has short stamens included in 

 the tube, while the style is long and projecting. In the other 

 kind of flower the stamens are long and projecting, while the 

 style is short and included in the tube. There is some dif- 

 ference between the pollen produced by the long stamens 



