166 
A NOTE ON THE INFLORESCENCE AND 
envelope soon appears to be in advance of the lower. This is particularly 
shewn in Strasburger’s figures of E. campylopoda 1 and by Land for 
E. trifurca 2 . Traces of this early inequality in development seem to be 
retained in later stages 3 . In the absence of further information it is quite 
possible that these relations are inconstant and unimportant. If however they 
represent the normal condition there is suggested the possibility that the 
male flower of Ephedra may be formed by a basipetally developing meristem 
as in Gneturn and that the latter genus differs from Ephedra in the circum- 
nodal extent of the meristem and in its long continued activity. And there 
arises the further question whether the envelope originates from the 
secondary axis or is merely concrescent with it. 
It can hardly be doubted that the male flowers of Gneturn and Ephedra 
are homologous structures and that one of them is more primitive than the 
other. All the probabilities are in favour of regarding Ephedra as repre- 
senting the earlier type. This receives strong support from the large 
number of anthers and the characters of the antherophore itself to which 
reference has already been made (p. 164). If so, in view of the absence of 
vascular tissue from the envelopes of Ephedra 4 and from that of at least one 
species of Gneturn, the normal presence of bundles in the envelope of Gneturn 
may well be a secondary character whose appearance is in response to 
physiological needs, and, therefore, without morphological significance. In the 
absence of direct evidence, this view is more probable than that which regards 
the envelope of Ephedra as a reduced form of a vascularised envelope such 
as that of Gneturn. 
It is easy, and perhaps not unusual, to attach too great importance to the 
details of the vascular system. But it is worthy of notice that the two 
bundles which normally supply the envelope of Gneturn lying in the antero- 
posterior plane, separate from that which supplies the two branches in the 
antherophore at a very low level. Frequently the separation occurs in the 
tissue of the primary axis (Fig. 12); when it takes place higher up it still 
necessarily occurs in that part of the secondary axis which is intercalated below 
the level at which the concrescence of the envelope with antherophore ceases. 
If the characters described above do not shew that the envelope is not 
composed of concrescent leaves, at least they cannot be disregarded by those 
who would make it a perianth. 
The question of the place of origin of the envelope has yet to be con- 
sidered. Does it arise from the secondary (floral) axis ? The envelope has 
now been shewn to be very distinctly basipetal (with regard to the main 
axis) in the order of its development. Its development is therefore very 
1 Strasburger, 1872, p. 133, Taf. xiv, figs. 2, 3. 2 Land, 1904, PI. i, fig. 3. 
3 L.c. figs. 1, 4 ; Thoday and Berridge, 1912, text fig. xx, 1. 
4 Except in E. fragilis, etc. (see p. 154). 
