560 
APPENDIX. 
[B. 
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 Conifers. 
To the earliest of the opinions here quoted , that which 
considers the female flower of Coniferee and Cycadem 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 v/here 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 shewn, 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 endea^ 
voured to support. 
In supposing the correctness of this opinion to be ad- 
mitted, a question connected with it, and of some im- 
portance, would still remain, namely, whether in Cycadese 
and Coniferse 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 else- 
where attempted to explain and defend, respecting the for- 
mation of the sexual organs in Phasnogamous plants f, 
whether the ovula in these two families originate in a 
modified leaf, or proceed directly from the stem. 
Diet. Class. d'Hist. Nat. tom. vi. p. 208. 
T Linn. Soc. Transact, vol. xiii, p. 211. 
