OF PLANTS CALLED COMPOSITE. 317 



reduced, the same alternation does not exist, especially in 

 those genera having vertically compressed pericarpia and 

 two aristae, as Spilanthus and Salmea. 



The absence of " discus epigynus" in Boopidece is a 

 necessary consequence of the accretion of the base of the 

 style with the tube of the corolla. It seems to me, how- 

 ever, that a modification of the same organ may be traced 

 in the five thickened areolae observable within and near the 

 base of the tube formed by the filaments in Acicarpha sjjci- 

 thdata ; and much more distinctly in the same situation 

 in Boopis balsamitifolia, where they have the appearance 

 of five adnate fleshy bodies alternating with the filaments. 



This apparent decomposition of the glandular disk in 

 Boopidece, compared with its state in Composite, as well 

 as its transposition and the alternation of its parts with the 

 stamina, seem to give some additional support to the con- 

 jecture I have formerly hazarded in the paper on Protectees, 

 published in the Society's Transactions (vol. x, p. 159 1 ); 

 namely, that in several families — for the hypothesis is not 

 meant to be extended to all — this part, even in its cui 

 simplest state, may be considered as formed of a series of 

 modified stamina : Or, merely to state the facts from which 

 the conjecture originates, that there are certain families in 

 some of whose genera this organ exists in its simplest form, 

 that of an undivided fleshy ring ; while in other genera of 

 the same families it consists of several distinct bodies alter- 

 nating with the stamina, and in some cases putting on the 

 appearance of barren filaments. 



This hypothesis is chiefly applicable to families in which 

 the number of stamina is equal to the divisions of one 

 floral envelope only, the nectarium being supposed to be 

 formed of the second series : but it receives its principal 

 support from Scitaminece, 2 where the glandular bodies 

 belong actually to the same series with the perfect stamen. 



I am aware at the same time of several objections to its 

 generalisation. Thus, the nectarium or glandular disk 

 exists in families where, though the stamina are definite, 



1 [Ante, p. 133.] 



2 See Flinders's Voyage to Terra Australis, ii. p. 574 [vol. i, p. 49]. 



