Page:Transactions of the Linnean Society of London, Volume 12.djvu/109

Rh an ingenious work on the natural families of plants, takes no notice of the vessels of the corolla in the character of Compositæ which he has there proposed.

In the figures of syngenesious plants given by Schkuhr, whereever the ligulæ of Cichoraceæ are magnified, the trunks of the nerves are correctly represented ending in the sinuses; unless in one plate containing Lactuca virosa and Sonchus sibericus, in both of which the vessels are made to pass through the axes of the teeth; but in no case are the marginal branches noticed. It is singular that this generally accurate author, in the many magnified figures he has given of tubular florets, has only in two cases represented the trunks of their vessels, namely in Echinops Ritro, where they are correctly placed, and in Silphium trifoliatum, where, though only five vessels are visible, they are erroneously made to pass through the axes of the laciniæ.

The only remaining author that notices these vessels is M. Mirbel, who in the second part of his valuable Elémens de Physiologic Végétale et de Botanique, published in 1815, introduces into his character of Compositæ the fact of the laciniæ of the corolla being furnished with marginal nerves. This observation, if not original, the author may have adopted either from my essay already quoted, of which he was in possession soon after its publication, or from M. Cassini's third memoir, which was read to the Institute of France six months after that essay appeared: but he could not have derived it from the passage in that author's second memoir, on which he rests his claim; no notice being there taken of the disposition of vessels in the laciniæ.

In M. Cassini's memoir expressly on the Corolla of Compositæ, which was read to the Institute of France in December 1814, and of which an abstract, by the author himself, is given in a late Rh