ORGANIZATION OF THE FOSSIL PLANTS OF THE COAL-MEASURES. JL 
belong to the nodal wood. The trachez of the foliar bundle, J, are spiral and 
scalariform. C.N.118*. x 150. 
PLATE 78. 
Calamites. 
Fig. 7. Part of a radial section, showing a leaf-trace bundle passing out through the 
nodal and secondary wood ; disorganized pith (p) is on the left. The nodal 
wood can be distinguished by its short traches. The leaf-trace consists of 
tracheze (on some of which the spiral thickening is seen) and surrounding 
parenchyma. ‘The section not being quite in the plane of the outgoing bundle, 
the latter appears to die out towards the right. px, protoxylem of bundle 
below the node. C.N. 22 x 100. 
Fig. 8. Part of a tangential section, showing a leaf-trace bundle cut transversely. 
The section passes through the inner part of the secondary wood. The 
pitting is almost entirely confined to the radial walls of the trachez. The 
shaded parts of the latter represent the unpitted tangential walls; the parts 
left white are in section; several secondary rays are shown (as at 7). Some 
of the tracheze show traces of transverse septa, but most of these appearances 
are due to oblique section of their tangential walls. The leaf-trace has a gap, 
where some of its primitive trachez are disorganized. It is surrounded by 
parenchyma. C.N. 20B, xX 100. 
Fig. 9. A. Short tracheide and neighbouring cells, in tangential section, to show 
bordered pits. Towards the parenchyma the border is unilateral (as at a). 
C.N. 204 (same specimen as 208, but from a section nearer the pith). x 200. 
B. Wall between two trachez, to show bordered pits, in tangential section. 
C.N. 1554 (shown in Plate 72, photograph 6), x 500. 
Fig. 10. Part of radial section, passing through a node. The pith is to the left. 
Above the node part of a primary ray (7) is shown. The canal of a bundle, 
containing remains of the protoxylem (px) passes up to the node from below. 
The protoxylem is continuous with the innermost elements of the nodal wood. 
The rest of the nodal wood is continuous with the persistent primary xylem 
(x) immediately outside the canal. C.N. 21. x 50. 
Fig. 11. Tangential section, to show course of vascular bundles. Three outgoing 
leaf-trace bundles are shown, in transverse section, at the node. Only the 
alternate bundles pass out at this node; the intermediate bundles do not pass 
out, but fork and attach themselves to the neighbouring strands. The relatively 
broad, small-celled rays (as at 7) show that the section passes near the pith. 
C.N. 26. x 13. 
Fig. 12. Part of transverse section, showing cortex and outer layers of wood (x). 
MDCCCXCIV,—B. 6 F 
