too much to sections merely, and have neglected
its appearance externally: and that those who have not at all examined it
in the early stage, have given the most correct account of its surface.
This account was founded on a very limited observation of ripe seeds,
generalized and extended to the unimpregnated ovulum, in connexion with
an hypothesis then very commonly received: but this hypothesis being soon
after abandoned, their statement respecting the ovulum was rejected along
with it.

In the ovulum of Kingia, the inner membrane, with relation to the
external umbilicus, is inverted; and this, as I have already observed,
though in direct opposition to M. Turpin's account, is the usual
structure of the organ. There are, however, several families in each of
the two primary divisions of phaenogamous plants, in which the inner
membrane, and consequently the nucleus, agrees in direction with the
testa. In such cases the external umbilicus alone affords a certain
indication of the position of the future embryo.

It is an obvious consequence of what has been already stated, that the
radicle of the embryo can never point directly to the external umbilicus
or hilum, though this is said to be generally the case by the most
celebrated carpologists.

Another observation may be made, less obviously a consequence of the
structure described, but equally at variance with many of the published
accounts and figures of seeds, namely, that the radicle is never
absolutely enclosed in the albumen; but, in the recent state, is either
immediately in contact with the inner membrane of the seed, or this
contact is established by means of a process generally very short, but
sometimes of great length, and which indeed in all cases may be regarded
as an elongation of its own substance. From this rule I have found one
apparent deviation, but in a case altogether so peculiar, that it can
hardly be considered as setting it aside.

It is necessary to observe, that I am acquainted with exceptions to the
structure of the ovulum as I have here described it, In Compositae its
coats seem to be imperforated, and hardly separable, either from each
other or from the nucleus, in this family, therefore, the direction of
the embryo can only be judged of from the vessels of the testa.* And in
Lemna I have found an apparent inversion of the embryo with relation to
the apex of the nucleus. In this genus, however, such other peculiarities
of structure and econo