M. Mirbel, in 1809,* held the same opinion, both with respect to Pinus and to the whole natural family.  But in 1812, in conjunction with M. Schoubert,** he proposed a very different view of the structure of Cycadeae and Coniferae, stating, that in their female flowers there is not only a minute cohering perianthium present, but an external additional envelope, to which he has given the name of cupula.

(Footnote.  Ann. du Mus. d’Hist.  Nat. tome 15 page 473.)

(**Footnote.  Nouv.  Bulletin des Sc. tome 3 pages 73, 85 et 121.)

In 1814 I adopted this view, as far, at least, as regards the manner of impregnation, and stated some facts in support of it.* But on reconsidering the subject, in connexion with what I had ascertained respecting the vegetable ovulum, I soon after altogether abandoned this opinion, without, however, venturing explicitly to state that now advanced, and which had then suggested itself.**

(Footnote.  Flinders Voyage 2 572.)

(**Footnote.  Tuckey Congo page 454 et Linnean Society Transactions volume 13 page 213.)

It is well known that the late M. Richard had prepared a very valuable memoir on these two families of plants; and he appears, from some observations lately published by his son, M. Achille Richard,* to have formed an opinion respecting their structure somewhat different from that of M. Mirbel, whose cupula is, according to him, the perianthium, more or less cohering with the included pistillum.  He was probably led to this view, on ascertaining, which I had also done, that the common account of the structure of Ephedra was incorrect,** its supposed style being in reality the elongated tubular apex of a membranous envelope, and the included body being evidently analogous to that in other genera of Coniferae.

(Footnote.  Dict.  Class. d’ Hist.  Nat. tome 4 page 395 et tome 5 page 216.)

(**Footnote.  Dict.  Class. d’Hist.  Nat. tome 6 page 208.)

To the earliest of the opinions here quoted, that which considers the female flower of Coniferae and Cycadeae as a naked pistillum, there are two principal objections.  The first of these arises from the perforation of the pistillum, and the exposure of that point of the ovulum where the embryo is formed to the direct action of the pollen; the second from the too great simplicity of structure of the supposed ovulum, which, I have shown, accords better with that of the nucleus as existing in ordinary cases.

To the opinions of MM.  Richard and Mirbel, the first objection does not apply, but the second acquires such additional weight, as to render those opinions much less probable, it seems to me, than that which I have endeavoured to support.

In supposing the correctness of this opinion to be admitted, a question connected with it, and of some importance, would still remain, namely, whether in Cycadeae and Coniferae the ovula are produced on an ovarium of reduced functions and altered appearance, or on a rachis or receptacle.  In other words, in employing the language of an hypothesis, which, with some alterations, I have elsewhere attempted to explain and defend, respecting the formation of the sexual organs in Phaenogamous plants,* whether the ovula in these two families originate in a modified leaf, or proceed directly from the stem.