328 PROCEEDINGS OF THE ACADEMY OF [1887. 



series of bractlets between the calyx and coi-olla, and that they have 

 become confluent with the corolla. On this tlieory the lobes of the 

 coroHa should be opposite and not alternate with those of the calyx. 

 After this theory had suggested itself, examination of the flowers 

 showed it was correct. The lobes of the corolla are opposite the 

 lobes of the calyx. 



The close relationship of RubiaceiB to Compositse has often been 

 remarked on. There are some correspondences in these observations 

 worthy of note: 



Mr. Darwin remarks (Effects of Cross and Self-fertilization, p. 

 173, 1877) that '' Composike are well adapted to cross-fertilization," 

 and Professor Asa Gray (A^nerican Agriculturist) adopts the same 

 view, referring to the ray-florets as if they were flags to attract in- 

 sects. Adaptation, is however, chiefly inferred from the fact that 

 the stigma, pushed up through the column of anthers, and cov- 

 ered with pollen, generally cleaves at the summit. The iuterior 

 faces thus seem destitute of pollen, and must receive it from some 

 external agency. The author of the present paper has, however, 

 shown by careful observation on the flowers of Chicory, that the 

 pollen grains fall into the cleft as the lobes of the stigma diverge. 

 Many experiments by enclosing flowers of different genera in fine 

 gauze, resulted in the florets seeding just as well as when exposed 

 to the visits of insects. He has, therefore, always contended that 

 the su])posed arrangements for cross-fertilization in Composifce were 

 deceptive, and that the species are generally closely self-fertilizers. 

 In further support of this view he has called attention to the fact 

 that in j)lants conceded to be dependent mainly on external aid for 

 pollen, a large nutiiber of flowers never get fertilized at all, while in 

 self fertilizers fiiilure rarely occurs. Compositce come squarely into 

 this class. The hermaphrodite florets rarely one nnght also add, 

 if ever fail to i)erfcct their seed. The remarkable fertility of the 

 self-poUenized florets in the heads of Cephalanthus, deserve to be 

 noted in correspondence with the self-pollenized florets of Compositce. 



The "bractlets" at the base of the flowers, are the analogues of 

 the scales on the receptacles of Compositor: 



The bractlets, or a cycle of floral parts similar to and succeeding 

 bractlets, unite with the corolla-tube, and form intra-lobular teeth 

 in Cephalanthus. May not certain forms of seta (Ilellanthus, He- 

 liopsis, etc.) be bractea that have become confluent with the calyx, 

 their apices forming the setaceous teeth ? It is difficult to determine 



