Pteridosperms and Angiosperms. 239 
In the Bennettitales on the other hand the great morphological 
feature, as compared with Cycads, is the high degree of modifi¬ 
cation met with in the reproductive organs. Whilst the vegetative 
habit is comparable to that of a dwarf and robust Cycad, and 
the anatomy is organised on essentially Cycadean lines, the fructi¬ 
fications take the form of laterally placed “ buds ” or “ cones ” usually 
found slightly projecting from between the persistent leaf-bases. 
The fructification consists of a short axis terminating in a convex 
receptacle. The proximal parts bear numerous scale-leaves, which 
are clothed with ramenta, recalling similar structures in recent 
ferns and in such Botryopterids as Zygopteris corrugatci. Between 
the enclosing “ bracts ” and the convex receptacle, the American 
specimens shew a whorl of from 10—18 frond-like microsporophylls. 
These remarkable organs, whose discovery and description we owe 
to Dr. W. R. Wieland, are pinnate in form and coalescent below ; the 
pinnae bearing double rows of synangia which contain the micro¬ 
spores. With the shedding of the spores the frond-like portions of 
the sporophylls withered or fell away leaving their coalescent bases 
as a circular collar or disc around the contracted neck of the 
convex receptacle. The receptacle itself is closely packed with the 
well known seed-pedicels, each of which ends in a straight seed, 
and interseminal scales which become enlarged distally to form 
a sort of pericarp, which, whilst enclosing the seeds, allows their 
micropyles to reach the surface. Thus in a few words are out¬ 
lined the salient features of the “ bisporangiate strobilus,” with the 
reconstruction of which Dr. Wieland has crowned the first stage 
of his labours on the American Cycadeoideae. 
We now come to the question of the morphological interpre¬ 
tation of this fructification. Whether it is to be regarded as “ an 
axis beset with sporophylls,” i.e. a flower, or whether, on the other 
hand, it is really a much more complex structure, i.e. an inflorescence 
or branch-system shewing extreme reduction. Even when the 
female fructifications of Bennettites alone were known, the pos¬ 
sibility of a close approximation to an angiospermous flower was 
recognised. 1 Now that we have precise details of the microsporo¬ 
phylls, the view taken by Dr. Wieland, that we have here a herma¬ 
phrodite flower, will meet with very general agreement. Looked 
at broadly and having regard to the pteridospermous affinities of 
the Bennettiteae this interpretation seems irresistable. To take 
the other view and read a“cyathium” into its structure seems to 
' See Scott’s “ Studies in Fossil Botany,” pp. 474—478. 
