Origin of Angiosperms 207 
bracts, forming collectively a kind of perianth and completely en- 
closing 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 com- 
partments 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. é 
The general arrangement of the organs is manifestly the same 
as in a typical Angiospermous flower, with a central pistil, a sur- 
rounding whorl of stamens and an enveloping perianth; there is, 
as we have seen, some approach to the closed ovary of an Angio- 
sperm; 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-lilies. It cannot, of 
course, be maintained that the Bennettiteae, or any other Mesozoic 
Cycadophyta at present known, were on the direct line of descent 
of the Angiosperms, for there are some important points of difference, 
as, for example, in the great complexity of the stamens, and in the 
fact that the ovary-wall or pericarp was not formed by the carpels 
themselves, but by the accompanying sterile scale-leaves. Botanists, 
