THE DICOTYLEDONES 1891 



ovary. The anthers are attached to the petals near the top of the tube and 

 well above the top of the style. It would appear therefore that when the 

 insect thrusts its proboscis into the flower to suck the nectar, the pollen 

 would be transferred from the anthers to the stigma. In practice however 

 this does not occur, because the pollen grains do not adhere to the dry 

 proboscis, but only to one wetted with nectar and hence the pollen is 

 picked up only during the withdrawal of the proboscis, and therefore after 

 it has passed the level of the stigma. Hence cross-pollination is usually 

 effected, but, should it fail, pollen will eventually fall on the stigma from 

 the anthers above and self-pollination is thereby ensured. 



In Forsythia the yellow flowers are homogamous, appearing early in the 

 year before the leaves. Nectar is concealed. Darwin thought that a hetero- 

 stylous condition occurred in Forsythia, but in gardens it is found that 

 F. suspensa is only short-styled whereas F. viridissima is long-styled. The 

 seeds from F. suspensa often produce F. intermedia which is apparently a 

 hybrid. In F. viridissima the style usually projects beyond the stamens so 

 that insects must first touch the style before meeting the mature anthers, 

 thereby effecting cross-pollination. In some flowers however the style is so 

 short that the stigma touches the anthers and self-pollination is inevitable. 

 The visitors are mainly bees. 



Another order, the Plantaginales, is somewhat nearly related to the 

 Oleales. It contains the single family Plantaginaceae. The members of 

 this family are annual or perennial herbs. The flowers are developed in 

 close heads or spikes and are usually hermaphrodite. There are four sepals, 

 four petals and four stamens, the latter having very long filaments with 

 versatile anthers containing much powdery pollen. The gynoecium has 

 two loculi containing many anatropous ovules. The fruit is a capsule with 

 circumscissile dehiscence; occasionally it is a nutlet. Pollination is usually 

 by wind. The chief genera are Plantago (Plantain) and Littorella (Fig. 1806) 

 in which the flowers are monoecious. Many consider that the family repre- 

 sents a degraded type, originating from the Scrophulariaceae. Plantago is 

 notable for its strongly marked protogyny. 



A further small order, the Campanulales, may also be mentioned here. 

 Their systematic position is uncertain, but they may be considered as 

 somewhat distantly related to the Compositae. The order includes several 

 small families of which the only important one is the Campanulaceae. 

 This family contains about sixty genera and 1,000 species. They are 

 temperate and subtropical herbs with alternate leaves, containing latex. 

 The inflorescence is generally racemose, though occasionally the flowers 

 may be solitary or cymosely arranged. The flowers (Fig. 1807) are herma- 

 phrodite, regular and pentamerous. In some, the odd sepal is anterior due 

 to the twisting of the bud through 180°. There are five stamens whose 

 anthers may be united. The gynoecium is multilocular and bears many 



