OF PLANTS CALLED COMPOSITE. 313
flower and fruit, of both species of Boopis in flower, and detached flowers and pericarpia of Calycera. In all of these I have found the ovulum pendulous ; and in Acicarpha and Calycera an inverted embryo occupying the axis of a fleshy albumen. My conjectures, therefore, on their struc- ci36 ture and relation to Acicarpha spathidata of the preceding paper, are completely verified by this examination, as well as by the observations of M. Cassini, who with his usual acuteness has detected the principal characters distinguish- ing Boopidece from Compositse and Dipsaceae, between which he has also placed them.
As M. Cassini's Memoir, though read subsequently to mine, is already published, the name Calycerece, which I have proposed for this family, is superseded by that which he has given it.
But as his account of the order is by no means complete, several characters of considerable, though not primary, im- portance being entirely omitted, I may be allowed to add to my paper some remarks on the more essential points of resemblance and difference between it and the two families to which it is most nearly related.
The principal characters distinguishing Boopidece from the whole of Composite are the pendulous ovulum and the albumen inclosing the embryo, of which the radicle points to the apex of the pericarpium. It appears to me necessary to state all these characters, and nearly in the terms in which they are here given : for, 1st, A pendulous ovulum most frequently, indeed, is not, however, invariably con- nected with radicula supera, though that direction of radicle might here, as well as in Compositse, with confidence have been inferred from the vascular structure of the ovulum. 1 2dly, Where the insertion of the ovulum is, as in this family, evidently below the upper extremity, the radicle
1 Some of the indications in many cases afforded by the structure of the uu- impreguated ovulum, of the position and direction of the parts of the future embryo, have hitherto been overlooked : the subject, however, for its elucida- tion requires details incompatible with the limits of the present communication. I have in another place (Flinders's Voyage to Terra Australis, ii. p. 601 [vol. i, p. 77]) thrown out a similarhint, which lias probably attracted no atten- tion, and must reserve the explanation of both for a separate essay.
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