EARLY SUMMER FLOWERS 179 



the corolla, spring on slender stalks from the inner surface of the 

 latter just where it widens out. The filaments are separate and 

 distinct, but the anthers are joined together edge to edge and 

 shed their pollen into the tube thus formed. The two lobes 

 of the bifid stigma are at first closed together, and are gradually 

 pushed up the anther tube by the growth of the style, only 

 unfolding when the pollen has all been swept out. 



The florets of the ray (Fig. 84, 3) have also an inferior ovary 

 and practically no calyx. The lower part of the corolla is tubular, 

 but the upper portion is prolonged on the side away from the 

 centre of the inflorescence into a white strap-shaped structure. 

 The free edge of this shows three minute teeth, which indicates 

 that three only of the five petals are concerned in the outgrowth. 

 A style and bifid stigma stand in the centre of the ray-floret, but 

 no stamens are present. 



The disc-florets are thus regular and have both stamens and 

 pistil, while the florets of the ray are irregular and are purely female. 



Insects visit the flower-heads, which are conspicuous objects, 

 in search of pollen and of the nectar secreted at the base of the 

 tubular corolla. In doing this they will come in contact with 

 florets of various ages. In those in an earlier stage pollen will 

 be swept out of the anther tube and the stigma will not have 

 appeared. In those at a later stage the pollen will have been 

 removed, and the receptive stigma will be exposed. The proba- 

 bility is therefore that the stigma will be pollinated from another 

 floret, and possibly from another plant. Cross-pollination must 

 take place in the case of the ray-florets, but the florets of the disc 

 may be self -pollinated if cross-pollination fails. This comes 

 about by the curving backwards of the lobes of the stigma in 

 old flowers, as was described for the Dandelion. 



The ovary develops into a one-seeded fruit (Fig. 84, 6, 7, 8), 

 which ultimately becomes detached from the flower-head but 

 has no special means of dispersal. 



The study of the Dandelion, Daisy, and Feverfew will enable 

 the student to understand the construction and mode of pollina- 

 tion of the flower-heads and flowers of a large family of plants, 

 to which belong, for example, the Thistles, the Hawk-weeds, and 

 the Ragworts. 



