PHYSIOLOGY OF THE FLOWER. 1 23 



Raspberry, blackberry, strawberry, apple, and hawthorn all agree 



in the possession of numerous stamens and excretion of honey- 

 by the receptacle. In blackberry the stigmas are mature before 

 the inner stamens, which turn outwards as they ripen. The last 

 three display well-marked proterogyny, and. except the straw- 

 berry, are sweet-scented. 



Roses do not excrete nectar, but are visited for pollen. The 

 styles and stigmas project in the centre, and form a landing- 

 place, so that crossing must often be effected, although many 

 stamens are mature at the same time. 



Gooseberry, red currant, and black currant possess small greenish 

 flowers, with minute petals, and live stamens. Nectar is excreted, 

 however, from the top of the inferior ovary, and the first is pro- 

 terandrous and self-sterile. 



Snoicdrop excretes honey in groves on the inner surfaces of the 

 small petals, upon which green streaks serve as honey- guide.-. 

 The pendulous flower is approached by flying insects from below, 

 when they are sure first to touch the stigma, which is placed on 

 the end of the simple style that projects beyond the six stamens. 

 The anthers dehisce by pores at their pointed ends, so that pollen 

 can readily fall out upon an approaching insect. 



Wallflower and stock do not present many remarkable features. 

 The stamens are tetradynanious, and the shortness of two of 

 them is partly due to the fact that they have to curve round two 

 of the nectaries, which are here small rounded green projections 

 of the receptacle between them and the ovary. Two other similar 

 nectaries are also present, one outside either pah* of long stamens. 

 The long claws of the petals are held firmly by the calyx against 

 the structures within, and an insect alighting upon the platform 

 constituted by the spreading limbs is, if already dusted with 

 pollen, pretty likely to deposit some on the stigma, and to carry 

 off a fresh supply while probing down to the nectar. 



Fuchsia is attractively coloured, and abundant honey is excreted 

 by the top of the inferior ovary. Pollination takes place as in 

 snowdrop, but the stigma is protruded more, and the anthers 

 dehisce by slits. In fuchsia and snowdrop there is no specialized 

 arrangement for causing pollen to fall upon insects. 



Heath (not heather) provides for this in a rather elaborate 

 way. The flower is pendant, and the contracted mouth of the 

 urceolate corolla (for the shape of which we shall now see a 

 reason) is almost blocked up by the style and stamens. The 

 former projects somewhat, ready (as in most pendulous flowers) 

 to receive pollen from approaching insects. The stamens, eight 

 in number, arise from a honey-excreting receptacle, and their 

 anthers form a ring round the style. The pollen escapes from 



