4 ANGIOSPERMAEDICOTYLEDONES 



' It is very interesting to observe how the various kinds of adaptation which are 

 associated in the largest order of flowering plants, the Compositae, making their 

 blossoms " the most successful of all flowers," are individually illustrated in the 

 various genera of Campanulaceae. Like all of the latter the Compositae are 

 markedly protandrous, and the two orders agree in the way in which the pollen 

 is deposited on the outside of the style to be carried away by insects, as also in 

 the bending back of the stigmatic branches to the pollen-bearing region of the style 

 so as to make automatic self-pollination possible. The aggregation of numerous 

 small flowers into a head surrounded by an involucre is exemplified by Phyteuma 

 and Jasione, which also agree with the Cympositae in the general accessibility of 

 their nectar, and the free projection of the reproductive organs from the flowers. 

 The union of anthers into a tube surrounding the style is indicated in Jasione, and 

 completely effected in Symphandra. The tubular character of the lower part of the 

 corolla, which in so many Compositae facilitates the ascent of nectar is exemplified 

 by Trachelium, and the annular nectary surrounding the base of the style is found in 

 Adenophora.' 



510. Campanula L. 



As Sprengel emphasized long since ('Entd. Geh.,' pp. 109-12), species with 

 flowers of the most various size agree in exhibiting marked protandry, and Hermann 

 Miiller adds that bees are particularly common visitors (' Fertilisation,' pp. 366-7). 



Fig. 212. Campanula pusilla, Haenke (after Herm. Muller). A . Longitudinal section of a young 

 bud. B. Reproductive organs of a bud ready to open. C. Ditto, of a Hower in the first (male) stage. 

 D. Ditto, of one in the second (female) stage, a, anthers ; , corolla ; fi, filaments ; gr, style ; grb, stylar 

 brush; grb\ ditto, after the hairs have shrivelled; , nectary; ov, ovary; po, pollen; .s, sepals; 

 sd, expanded bases of filaments, fringed with hairs and serving as nectar-covers ; st, stigmas. 



The flowers are mostly blue in colour, and Herman JNIuller states that the 

 nectar is secreted by a yellow fleshy disk situated on the ovary and surrounding the 

 style. It is covered by the triangular lower parts of the filaments, and further 

 protection is aff"orded by interlocking hairs that close the spaces between these five 

 valves. The three short stylar branches are at first apposed to form a cylinder 

 thickly clothed with long erect hairs, and so closely surrounded by the anthers in the 



