Hickling . — The Anatomy of Palaeostachya vera. 381 
the only feature of importance which distinguishes the Bornia cones from 
Calamostachys is the entire absence of bracts, and as this feature is not 
constant in Bornia itself, the relations of that genus need not be separately 
considered. Cingularia offers no ground for detailed comparison, as its 
internal anatomy is entirely unknown. Only Calamostachys remains. 
Here there seems to be a fundamental difference. Nodes surrounded by 
bracts alternate with nodes surrounded by sporangiophores. So we have 
said. But I think there is already sufficient evidence to throw serious 
doubt on that statement. Renault 1 describes the vascular supply of his 
Calamodendrostachys Zeilleri in these words ‘ Dans l’esp^ce que nous 
avons figuree on compte quatorze coins ligneux, chacun muni d’une 
lacune, i (Figs. 5 et 6) ; de chaque cote se trouvent de petits faisceaux 
ligneux, muni ou non de lacunes, i', qui apres s’etre eleves dans 1’entre- 
nceud, au-dessus des points d’insertion des sporangiophores, sp. y redescendent 
pour y penetrer en restant a la partie superieure de la portion horizontale 
de ces organes. Les petits faisceaux dont nous venons de parler sont 
au nombre de quatorze, et forment, dans une grande portion de l’entre- 
nceud, une couronne tres grele discontinue en dehors du circle des fais- 
ceaux principaux ; ils separent de ces derniers au-dessus du verticille de 
bractees steriles immediatement place au-dessous du verticille fertile que 
l’on considere, s elevent verticalement dans 1’entre-noeud, puis redescendent 
pour penetrer dans les pedicelles des bractdes fertiles/ It seems scarcely 
possible to doubt that the ‘ petits faisceaux * are the strict homologues of 
our sporangiophore-traces. As in Palaeostachya , they are equal in number 
to the principal bundles, they separate from them ‘ au-dessus du verticille 
de bractees steriles,’ they ascend vertically in the internode, and are then 
reflexed to pass into the sporangiophores. The reflexed portion of the 
trace is not carried so far down as in Palaeostachya , and the traces are not 
radially opposite the principal bundles, but alternate with them. These 
appear to me to be the only two structural differences of classificatory 
importance between C. Zeilleri and Palaeostachya. 
In our English Calamostachys it was commonly assumed that the 
sporangiophores represent independent fertile whorls. The influence of 
the ventral-segment theory of the sporangiophore has thrown doubt on 
this. Williamson and Scott 2 noticed that the principal bundles passed the 
fertile ‘nodes’ without interruption of their protoxylem canals, and state 
that ‘the fertile nodes .... show scarcely any modification of structure 
as compared with the internodes.’ In a fine longitudinal section of a Cala- 
mostachys with the pith preserved (Manchester Museum Coll. Q. 295), it is 
a striking feature that the pith cells are ‘ shortened-up ’ at the level of the 
bracts, while they pass by the sporangiophores unchanged. These facts 
appear to me to raise the strongest doubt against the view that the 
1 Renault, ’ 96 , p. 130, PL LX, Figs. 3-8. 2 Williamson and Scott, ’ 94 , pp. 905-6. 
