280 
HICK : 0ALAMOSTACHYS BINNEYANA. 
of sections cut by Mr. James Binns, of the same town, in which the 
structure of the spike is so well preserved as to give much addi- 
tional information on important points of detail, clear up others 
that have hitherto been doubtful, and at the same time throw 
considerable light on the question of affinities. 
The general structure of Calamostachys Binneyana, as hitherto 
described, may be summarised as follows : — 
The axis of the spike consists of a series of nodes and inter- 
nodes, the former of which bear alternately whorls of sterile bracts 
and sporangiophores. The nodes bearing bracts are extended out- 
wards to form what Williamson has termed the " nodal disks." 
From the margin of each disk, the bracts, usually twelve in number, 
are given off, and these turning upwards ascend beyond the bases of 
the members of the next higher whorl, with which they alternate. 
The sporangiophores are placed about midway between the " nodal 
disks," and stand at right angles to the axis. Their distal ends are 
dilated into peltate heads to the inner surface of which the sporangia 
are attached, of which each carries four. Hence, as has often been 
pointed out, the spike bears a strong resemblance to that of Equi- 
setum, the chief difference being the intercalation of a " nodal disk" 
with its sterile bracts between the successive whorls of sporangio- 
phores. 
As regards the histology of the strobilus the authorities referred 
to were not in a position to obtain final and decisive results, and 
hence perhaps their divergent views. In dealing with it, it will con- 
duce to clearness if w r e first epitomise the statements already pub- 
lished, and then present the results obtained by a study of the fresh 
material. 
The Axis or the Strobilus. 
Carruthers in the paper already referred to writes of the axis as 
follows : — "The axis of the strobilus has a bundle of fine scalariform 
tissue in its center, forming about a third of its diameter, and gener- 
ally appearing free from the surrounding cellular tissue which is 
composed of somewhat elongated cells."" 
* Loc. cit., p. 350, 
