Primitive Angiosperms. 139 
living forms which represent such ancestors are considered as the most 
primitive flowers known. 
Three objections are raised against this view. ‘ In the first place 
it must be assumed that the perianth is evolved de novo , and is an organ 
sni generis . Secondly, in many of the groups regarded as primitive, e.g. 
Peperales, Amentiferae, and Pandanales, the inflorescence is a sharply 
defined and often a highly complicated structure. Lastly, such a theory 
has so far proved barren from a phylogenetic standpoint, especially when 
the attempt is made to bring into line evidence derived from the study 
of fossil plants’ (Arber and Parkin, p. 39). 
The first difficulty is obvious and hardly requires comment. The 
second must be attacked by taxonomic methods. The third is that which 
the authors develop at greatest length. 
The substance of their argument is that the strobilus or cone is a very 
ancient type of fructification among Cryptogams and Gymnosperms, and 
that such a flower as that of the Magnolia can be interpreted as a bisexual 
strobilus in which the male sporophylls stand below the female, and both 
are protected by a special series of sterile leaves forming a basal perianth. 
Dr. Wieland ( 89 ) has recently shown that American members of the 
Bennettiteae possessed bisexual strobili of a form hitherto unknown. The 
male sporophylls stood below the female, and a number of sterile leaves 
below both. This form of strobilus may be fairly compared with an 
Angiospermous flower of the Ranal type. It is acknowledged that the 
individual Bennettitean sporophyll, male or female, differs very widely from 
the corresponding organ in Angiosperms. The points which the fructifica- 
tions have in common are the arrangement of sporophylls of both sexes 
on a single axis, their relative position on that axis, and the presence of 
sterile members at its base. 
In short, the description of the amphisporangiate strobili belonging 
to members of the Bennettiteae has suggested a possible origin for the 
Angiospermous flower (Wieland, 89 , p. 245 ; Scott, 80 , p. 139). There is 
nothing forced or unnatural about the scheme of development worked out 
in detail by Messrs. Arber and Parkin. But any such scheme requires 
that the more recent ancestors of our living Angiosperms should have 
borne flowers of the anthostrobiloid type, that is, flowers in which perianth 
leaves, stamens and carpels are arranged on the axis in acropetal succession. 
Such flowers are actually found among living Angiosperms. They have 
been considered primitive on taxonomic grounds by many authorities in 
the past, and are still thought to be so by some modern botanists. Their 
claims to antiquity are certainly much strengthened by the resemblance 
lately discovered between certain of their features and the corresponding 
features in extinct forms with Gymnospermous seeds. 
It may perhaps be objected that the resemblance is superficial. Why 
