mber of spirally arranged bracts,
forming collectively a kind of perianth and completely enclosing the
essential organs of reproduction. The latter consist of a whorl of
stamens, of extremely elaborate structure, surrounding a central cone
or receptacle bearing numerous ovules. The stamens resemble the fertile
fronds of a fern; they are of a compound, pinnate form, and bear
very large numbers of pollen-sacs, each of which is itself a compound
structure consisting of a number of compartments in which the pollen
was formed. In their lower part the stamens are fused together by their
stalks, like the "monadelphous" stamens of a mallow. The numerous ovules
borne on the central receptacle are stalked, and are intermixed with
sterile scales; the latter are expanded at their outer ends, which are
united to form a kind of pericarp or ovary-wall, only interrupted by the
protruding micropyles of the ovules. There is thus an approach to
the closed pistil of an Angiosperm, but it is evident that the ovules
received the pollen directly. The whole fructification is of large size;
in the case of Cycadeoidea dacotensis, one of the species investigated
by Wieland, the total length, in the bud condition, is about 12 cm.,
half of which belongs to the peduncle.

The general arrangement of the organs is manifestly the same as in a
typical Angiospermous flower, with a central pistil, a surrounding whorl
of stamens and an enveloping perianth; there is, as we have seen, some
approach to the closed ovary of an Angiosperm; another point, first
discovered nearly 20 years ago by Solms-Laubach in his investigation of
a British species, is that the seed was practically "exalbuminous," its
cavity being filled by the large, dicotyledonous embryo, whereas in all
known Gymnosperms a large part of the sac is occupied by a nutritive
tissue, the prothallus or endosperm; here also we have a condition only
met with elsewhere among the higher Flowering Plants.

Taking all the characters into account, the indications of affinity
between the Mesozoic Cycadophyta and the Angiosperms appear extremely
significant, as was recognised by Wieland when he first discovered the
hermaphrodite nature of the Bennettitean flower. The Angiosperm
with which he specially compared the fossil type was the Tulip tree
(Liriodendron) and certainly there is a remarkable analogy with
the Magnoliaceous flowers, and with those of related orders such as
Ranunculaceae and the Water-lilie