ll is formed in the female cell, and this either becomes the embryo, or
gives origin to another cell, and so on, until the terminal one becomes
the embryo.

I believe from examination of the most developed scaly ramenta, that
these have at an earlier period been fecundating organs, the same
peculiarities are to be detected towards their ends, where in fact they
retain their original structure, the dilated base being a subsequent
development.

In reference to this, the examination of young ferns on their arrival at
the age of puberty is indispensable. A curious question arises, what is
the frond of a fern? Is it a mass of foliaceous growth containing
certain lines of reproductive matter, or is it a distinct development
from the axis, in which the reproductive organs are situated? Is it, or
is it not, subservient to reproduction? Here again extensive examination
is necessary.

If it is altogether subordinate to reproduction, we may expect the
occurrence of far more simply constituted ferns than we are yet
acquainted with. In fact we may expect a form reduced to an axis, a few
ramenta, a frondose dilatation, and one punctum of reproductive organs.

With respect to duration, each frond is analogous to a single seta of a
moss, it has definite limits, and is unlike the fronds of certain
Hepaticae, which are capable of compound growth; or if this is the case
in ferns, as it is in viviparous ferns, the new formation becomes
separated from the frond, as a Phaenogamous gemma does. This is a
question of importance, as perhaps it may prove that all the foliaceous
forms, except Lycopodium, Equisetum, and Chara, are frondose; the dorsal
situation is in favour of this assumption, since in all the genuine
frondose forms, the reproductive organs of both kinds originate
immediately from the under surface, although they may protrude through
the upper.

I here ask, is there not _prima facie_ evidence that these organs have
peculiar functions; a peculiar form, attended with peculiar changes, must
have peculiar functions; and will any one show me in any single instance,
like circumstances to the like extent, in any of those organs called
hairs? By the bye, ferns themselves may prove that however like these
are to certain forms of hair, yet that their functions are different,
because the glandular hairs of ferns do not undergo the same alterations,
and are evidently nothing but hairs, probably secretory.

_19th_.--In Ceterach th