JSemale Flower in Cycadee and Conifere. 415 
servations, that the apex of the nucleus, or supposed point of 
impregnation, has no organic connexion with the parietes of 
the ovarium. In support of it, also, as far as regards the di- 
rect action of the pollen on the ovulum, numerous instances of 
analogous economy in the animal kingdom may be adduced. 
The similarity of the female flower in Cycadeze and Coni- 
ferze to the ovulum of other phenogamous plants, as I have 
described it, is indeed sufficiently obvious to render the opi- 
nion here advanced not altogether improbable. But the proof 
of its correctness must chiefly rest on a resemblance, in every 
essential point, being established, between the inner body in 
the supposed female flower in these tribes, and the nucleus of 
the ovulum in ordinary structures ; not only in the early stage, 
but also in the whole series of changes consequent to fecunda- 
tion. Now as far as I have yet examined, there is nearly a 
complete agreement in all these respects. I am not entirely 
satisfied, however, with the observations I have hitherto been 
able to make on a subject naturally difficult, and to which I 
have not till lately attended with my present view. 
The facts most likely to be produced as arguments against 
this view of the structure of Coniferae, are the unequal and ap- 
parently secreting surface of the apex of the supposed nucleus 
in most cases; its occasional projection beyond the orifice of 
the outer coat; its cohesion with-that coat by a considerable 
portion of its surface, and the not unfrequent division of the 
orifice of the coat. Yet most of these peculiarities of structure 
might perhaps be adduced in support of the opinion advanced, 
being apparent adaptations to the supposed economy. 
There is one fact that will hardly be brought forward as an 
objection, and which yet seems to me to present a difficulty, to 
this opinion; namely, the greater simplicity in Cycadez, and 
in the principal part of Conifers, of the supposed ovulum 
which consists of a nucleus and one coat only, compared with 
the organ as generally existing when inclosed in an ovarium. 
The want of uniformity in this respect may even be stated as 
another difficulty, for in some genera of Coniferze the ovulum 
appears to be complete. . 
In Ephedra, indeed, where the nucleus is provided with two 
envelopes, the outer may, perhaps, be supposed rather analo- 
gous to the calyx, or involucrum of the male flower, than as 
elonging to the ovulum; but in Gnetum, where three enve- 
lopes exist, two of these may, with great probability, be re- 
garded as coats of the nucleus ; while in Podocarpus and Da- 
crydium, the outer cupula, as I formerly termed it*, may 
also, perhaps, be viewed as the testa of the ovulum. To this 
* Flinders’s Voy, vol. ii. p. 573. , 
view, 
