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ON THE SEXUAL ORGANS OF TUE CYCADACE^. 99
and the Gymiiosperms, not only fills up, to a certain extent, tbe gnp
which has hitherto separated the Phanerogains and the Cryptogams (a
point which has been lately developed by Kirchhoff in a note full of in-
terest inserted in the ' Botanische Zeitung,' 1867, Nos. 42, 43), but it
renainds us that it was precisely the vascular Cryptogams and Gym-
nosperms which, up to the Cretaceous epoch (omitting from conside-
ration a small number of Monocotyledons), represented the higher
plants. The passage to the more complicated forms of Phanerogams,
with hermaphrodite flowers and angiospermous structure, is exhibited
to us by existing types of Gymnosperms. This is shown in the
genera Ephedra and Gnetum (the last having two ovular coats) l)y the
structure of their stem, by their leaves, and by the nidimentary perigo-
nial envelopes of the still naked ovules. TFehcitscJua, the structure of
which has been so completely made out by the excellent work of
Hooker, though reminding us of Cycads by the form of its stem, of
tropical Coniferae by its leaves, and of Gnetum. hs its inflorescence,
makes, on the other hand, the first step towards hermaphroditism (as
yet unknown amongst the earliest Phanerogams up to the Cretaceous
period, and perhaps even later) by the development of male organs
within the same perigonium as a naked ovule. From this point organi-
zation advances a step in passing to the group of Loi-antJiacete, re-
garded with the inter])retation that Baillon has attached to it (' Me-
moire sur les Loranthacees '). In TFthoitschia hermaphroditism is
still incomplete ; in the LorantJiacece we find its stage of development
more advanced Looked at in this way, rudimentary organs appear not
as atrophied parts, but as the first step towards a more complicated
plan of organization, which is only realized slowly in the progress of
time.
In agamic generation, individuals are reproduced with all their cha-
racters; they form, as it were, an indefinite chain of identical ramifica-
tions, and it is rare for this mode of reproduction to give origin to a
deviating form.* In sexual generation this constancy of forms and
characters is not possible. The two individuals which give origin to a
* "We must not accept this statement without limitation, if it is to include
all cases of agamic reproduction. In Bud variation in plants we have instances
of new forms originating independently of sexual reproduction. The
production of fleshy peach-like fruits by the Double Almond (Darwin, ' Animals
and Plants under Domestication,' vol. i. p. 338), and of nectarine-bearing
branclies by Peach-trees (Darwin, p. 37 J^) are examples.—W. T. D.