150 
SPORANGIOPHORES AND SPOROPHYLLS 
bracts or leaf-teeth: thus, in the modern Zgwzsefvm and in the ancient 
ornia they occupy the whole strobilus in large numbers, and bracts are 
absent ; in Phylotheca the fertile spikes are interrupted by occasional whorls 
of vegetative leaves: in Calamostachvs the strobilus bears successive whorls 
of bracts, and whorls of sporangiophores alternate with them ; but even here 
they do not show exact numerical correspondence with the bracts, which, 
moreover, alternate 
independently of them. 
Further, their longitudinal 
Fic. 8&1. 
Palacostachya. Diagram of cone in 
radia] section. a@x=axis, which bears 
verticils of bracts (47) with peltate 
sporangiophores (sf) in their axils. 
sm =sporangia. (After Renault.) From 
Scott. 
Fic. 82. 
Archacocalamites. Part ot 
cone showing the axis (a1) 
in surface view, bearing 
superposed verticils of peltate 
sporangiophores (sf) without 
bracts. sz=sporangia. (After 
Renault.) From Scott. 
Fic. 83. 
Helminthostachys seylanica. 
Young spike in oblique profile : 
the primordia of sporangio- 
phores are densely clustered on 
the margin. Magnified. (After 
Goebel.) 
position relatively to the bracts varies, for in Ca/amostachys they are placed 
midway between the whorl of bracts, in Padacostachva in their axils, 
Cingularia immediately below them. 
in 
This indefiniteness of relation of 
the spore-bearing bodies to the bract-leaves in number and_ position, 
seen among the Equisetales, when taken together with the difference of 
function, points to their being a separate category of members from them 
(Figs. 80, 81, 82). 
1 This statement is not in accord with the opinions expressed by Prof. Lignier, which 
will be considered where the Equisetales are specially treated in Part IT. 
