979 
the Inflorescences and Flowers of Ephedra . 
the little axis on which it is borne represents an axillary bud, for it bears no 
leaves. But the male flower has already been compared with a little 
strobilus, and it seems probable in view of the evidence of reduction in the 
family that the female flower also represents a very reduced strobilus. 
If like the male flower it is to be compared with the strobilus of the 
Bennettitales, then the single ovule must represent the whole ovulate cone 
in that family ; the comparisons which have been made by other authors 
between the male flower of W elwitschia and the Bennettitean strobilus 
necessitate this presumption, and direct evidence of such a fusion of ovules 
and their coverings has here been recorded in E. altissima , where the single 
terminal ovule represents the two fused axillary ovules of other species. 
It seems that while there is strong evidence that the male sporangia 
are foliar, we are driven to the view that the ovule terminates an axillary 
shoot. In the Bennettitales also the male sporangia are undoubtedly 
foliar, but we are still not certain as to the seed, though the view that the 
seed pedicel is the equivalent of an interseminal scale and therefore foliar 
appears to be gaining ground. If the single ovule in Ephedra and Wei - 
wits chia represent the mass of foliar ovules and scales in Bennettites , being 
derived by reduction and fusion from a strobiloid condition probably more 
simple than that actually found in that family, this difference between male 
and female sporangia would be accounted for. 
The single ovule now differentiated direct from the plastic apex of the 
axillary bud would thus be the equivalent of more than one ovule, each 
originally borne on a foliar organ, but now fused together at the apex of an 
axis, much as the apical pair of synangia in E. altissima and perhaps the 
single trilocular synangium of W elwitschia are the equivalent of several 
pairs of synangia originally borne on foliar appendages, but now fused 
together at the top of what falsely appears to be a cylindrical axis since it 
shows so little trace of its primitively bifid and leaf-like condition. It may 
be that there is as yet insufficient evidence for this analogy between micro- 
and megasporangia, but at any rate the great amount of reduction which the 
microsporophyll has undergone, even among existing forms, as evidenced by 
its variation from a leaf-like organ bearing eight synangia to a small 
cylindrical axis carrying only two, renders it quite probable that in the 
female flower also we have the final stage of a long series of reductions, the 
last trace of which is still to be seen to-day in the fusion of ovules in 
E. altissima. 
IV. Comparison of the Inflorescences of the Three Members 
OF THE GNETALES. 
Of the three genera of the Gnetales it appears from their anatomy 
that Ephedra and W elwitschia are most closely related to one another. 
The dichasial branching of the male inflorescences of all species of Ephedra 
