Notes. 719 
are sterile and serve to form the involucre, while the others bear the 
ovules.’ 
In carefully pondering over the morphological character of the 
fructification of the fossil plant under consideration, I cannot resist 
the final conclusion that the view which regards the seminal stalks or 
* cords' as being foliar in nature is the only admissible and correct 
one. Further, I adopt the view put forward by Celakovsbf \ viz. that 
the sporophyll is originally and primitively radial in structural sym¬ 
metry, bearing the sporangium in a terminal position. 
This view is founded on the theory that all vascular axes with their 
appendages, the foliar organs, have had their origin in the sporogonium 
of a Bryophyte such as Anthoceros. This sporogonium is a structure 
of essentially radial symmetry y its earliest branches or appendages 
must necessarily also have possessed the same character. As sterili¬ 
zation proceeded apace in these radially-constructed appendages, the 
sporogenous tissue would become for obvious reasons projected 
towards the apex of the appendage and would thus in time come to 
represent a sporangium situated terminally to its radially-constructed 
sporophyll. This type of compound sporogonium or of strobilus is 
preserved for us in the female cone of Ginkgo , and in Osmunda and 
a few other Ferns. In modern Cycads there is a clear case of 
transition from the radial type of sporophyll to the later dorsiventral 
type, and in Angiosperms, at least on the female side, this transition 
has become complete, where the carpels are always dorsiventral in 
construction and bear the ovules marginally or ventrally. This latter 
type of sporophyll, therefore, is that which is found in the group of 
plants which stand highest on the evolutionary scale, and represents 
thus the type towards which all primitive radially-constructed sporo- 
phylls must evolve, for it is obviously the one best adapted for the 
purposes of fertilization and dissemination of the seed. 
It is on account of the above views that I regard the fructification 
of Bennettites as being essentially more primitive in character than that 
of modern Cycads, in contradistinction to the view hitherto propounded 
that in the cone of Bennettites we see an advance, beyond that of 
modern Cycads, in the Angiospermous direction. In my opinion, no 
advance may rightly be spoken of except in connexion with those 
essential organs of a plant which have always formed the basis for the 
1 Celakovskf, Nachtrag zu meiner Schrift liber die Gymnospermen; Engler’s 
Jahrbuch, 1897. 
3 ® 
