380 Hickling. — The Anatomy of Palaeostachya vera. 
I interpret the dark mass in the centre as the shrunken and carbonized 
remains of the cell-contents. 
Williamson , 1 however, regarded the outer wall as belonging to the 
spore mother-cell, and stated that each mother-cell contained a single 
spore. This view would be possible if we regarded the spores as mega- 
spores. Against this we have the fact that they would be rather small — 
they are just about the same size as the spores of Calamostachys Bin - 
neyana — and, further, in view of the fact that the ‘ mother-cell ’ wall is still 
not degenerated, we might fairly expect to find traces of the remaining 
spores of the tetrad, such as are found in C. Casheana. A careful search 
has failed to show anything which could possibly be interpreted in this 
way. I think it would also be rather surprising that all the cones should 
be macrosporous. Hence in the evidence available I see no ground for 
the assumption of heterospory, which this view seems to involve. 
There are no other points regarding the spores which call for comment. 
Affinities of the Cone . It is not intended to enter into any elaborate 
discussion of this question, since I do not consider that it can profitably be 
done without a complete reinvestigation of our knowledge of the fructifi- 
cations of the Calamarieae. The only point which is really vital to this 
paper is whether or not the new features of the cone, now brought to light, 
necessitate such a revision of our ideas as to its affinities as would cause us 
to take it out of the genus it is supposed to belong. The Equisetales and 
Sphenophyllales, which groups I regard as more closely associated than 
generally suggested, all agree in having cone-like fructifications, in which 
the sporangia are borne on stalked sporangiophores ; rarely directly on 
leaf-like organs. The cones of the two phyla broadly differ, those of the 
former having sporangiophores attached to the axis of the cone, while in the 
latter the sporangiophores are attached to the leaf-like bracts. Further, the 
Calamarieae have typically four, the Sphenophylleae one or two sporangia 
on each sporangiophore. Of course the former, too, are generally without 
the centripetal wood possessed by the latter. The fact that the two cones 
more recently described by Dr. Scott, Cheirostrobns 2 and Sphenophyllum 
fertile , 3 between them reduce the separation of Calamarian and Spheno- 
phyllaceous cones to a matter of the type of primary wood, does not affect 
the present question. Palaeostachya has only one character in which 
it in any way even appears to approach the Sphenophyllum group : 
its axillary sporangiophores. This feature we have seen to be totally 
deceptive, and hence we may confidently assert that our cone is not to be 
placed on the Sphenophyllaceous side of the Calamarian series. Among 
the Calamarian cones themselves, two other types are known from petrified 
material — Calamostachys and Bornia — while Cingularia must be made the 
type of a fourth group still unknown among our petrified remains. Since 
1 Williamson, ’87, p. 53 . 2 Scott, ’97. 3 Scott, ’05. 
