GENERAL MORPHOLOGY BS 
of twelve coherent leaves, but thirteen have been counted: the sporangio- 
phores are usually six, that is, half the usual number of the leaves of the 
sterile whorls; but seven and eight have been seen in a single whorl of 
them, while no whorl of sixteen bracts has been seen. Hence it is clear 
that the sporangiophores bear no strict 
numerical relation to the sterile bracts. 
The position of the bracts in successive 
whorls of them alternates: the successive 
whorls of sporangiophores, on the other 
hand, do not alternate, ‘but are placed one 
above the other in vertical rows. Hence it 
is evident that their position can bear no 
constant relation to that of the bracts.” 
This absence of a strict relation of the 
sporangiophores to the bracts comes out 
also in C. Ludwigr, described in detail by 
Weiss.2, He remarks of this species that 
the number of leaves in the sterile whorl is 
evidently variable: he made several count- 
ings, and concludes, ‘accordingly it may 
be accepted that there were sixteen leaves 
in the whorl, but that they might be re- 
duced to twelve (or thirteen?) by abortion 
of some of them.” The leaves of the 
neighbouring whorls certainly alternated. 
Of the sporangiophores he says, the number 
in each whorl is six, and the successive 
whorls of sporangiophores stand vertically 
above one another; but he notes slight 
deviations from this, perhaps due to torsion. 
A still further step is depicted by Weiss,® 
in the case of Calamostachys germanica, 
where apparently the narrow bracts are 
approximately three times the number of — parmeostachya pedunculata. Specimen 
the sporangiophores; but this is not speci- ftom, the soalshales, showing a fertile 
shoot bearing about a dozen cones, and a 
; . few leaves. #=stem. About two-thirds 
fically stated to be the case in the text. natural size. (After Williamson, P/2?. 
On the other hand, it has been shown = Z7aus. Will. Colt., 1060.) From Scott's 
Studies in Fossil Botany. 
Fic. 200. 
clearly in the case Padaeostachya vera that 
the number of bracts approximately corresponded directly to the number 
of sporangiophores, though possibly in some cases they somewhat exceeded 
1 Williamson and Scott, ‘‘ Further Observations on the Organisation of Fossil Plants, etc.,” 
part i., Phil. Zrans., 1894, B, pp. 902-3. See also Scott, Stadies, p. 47, etc. 
2 Abhandl. z. Geol. Spestalkarte, vol. ii., part 1., p. 38. 
3Z.¢., vol ii., part i, Taf. xvi., Fig. 3 2. 
