Palaeontologie. 
183 
The authors conclude that the nature of a typical Angiospermous 
flower is essentially that of a strobilus or cone, and this is termed 
the ‘Strobilus Theory of the Angiospermous Fructification.’ They 
restrict the word “flower” to the Angiosperms alone. They regard 
the most primitive existing flower as being an amphisporangiate 
strobilus, and the simpler unisexual flowers, including apetalous 
forms, as derived from such a strobilus by reduction. They conclude 
that the typical strobilus of the Angiosperms, and of certain Mesozoic 
plants, differs from the cones of all other plants, and this t} T pe of 
Strobilus they term a Anthostrobilus. Of the Anthostrobilus they 
distinguish two forms, quite distinct from one another. 
/ Pro-anthostrobilus of Mesozoic Ancestors and 
Anthostrobilus ' Bennettiteae. 
f Eu-anthostrobilus (or Flower) of Angiospermeae. 
The anthostrobilus differs from all other cones in that it is typically 
amphisporangiate, and possesses a distinct perianth, and in the fact 
that the megasporophylls are invariably aggregated on the axis of 
the strobilus above the microsporophylls. In the Eu-anthostrobilus 
the megasporophylls are closed, and the microsporophylls have the 
form which we call a stamen, while in the Pro-anthostrobilus, the 
former did not function as pollen-collectors, and the latter were 
fernlike fronds bearing synangia. Both cones represent different 
stages in the evolution of the fructification of one and the same line 
of descent. The anthostrobilus is the newest modification or creation 
of the strobilate form of fructification, in point of geological time. 
The authors next criticise, on three grounds, Engler’s Theory 
(as opposed to the Strobilus theory) that the primitive type of An- 
giosperm fructification is to be sought for among the unisexual 
Apetalae. In the first place it assumes that the perianth is evolved 
de novo, and is an organ sui generis. Secondly, in many of the 
groups which En gier regards as primitive, the inflorescence is a 
sharply defined, and offen a highly complicated structure. Thirdly 
such a theory is barren from a phylogenetic standpoint, especially 
when the attempt is made to bring into line evidence derived from 
the study of fossil plants. The Pipernies, Amentiferae , Pandanales 
and Araceae are discussed in this connection. 
The next section of the paper is devoted to a consideration of 
the primitive form of the Organs of the Eu-Anthostrobilus or Flo¬ 
wer. A drawing is given of a cone in which all the Organs are alike 
primitive, though in all probability such a cone never existed. The 
cone was hypogynous and polypetalous. The axis, which was large, 
elongate and conical, bore megasporophylls above, and microsporo¬ 
phylls below, and at the base a well marked perianth was present. 
All the organs of the cone were of large size, numerous or indefi¬ 
nite in number, and spirally arranged. The gynaecium consisted of 
many apocarpous monocarpellary ovaries, each containing several 
ovules with marginal placentation. The ovule was orthotropous, 
with two integuments. The embryo germinated within a short period 
after fertilisation, and possessed two epigeal cotyledons. The androe- 
cium consisted of an indefinite number of stamens with longanthers, 
but short filaments. The perianth was formed of numerous spirally 
arranged members, either all alike in form, colour etc., or perhaps 
somewhat differentiated. The mode of fertilisation was entomophilous. 
Some of these primitive features are retained by certain members 
of the Magnoliaceae, Ranunculciceae, Nymphaeaceae, Calycanthaceae, 
Alismaceae and Pahnaceae. Primitive features, as regards the mega- 
