ORGANIZATION OF THE FOSSIL PLANTS OF THE COAL-MEASURES. 947 
cortex well preserved. Several layers of secondary wood have already been 
formed. Outer part of the pith persistent. C.N. 1553. x about 15. See 
also Plate 77, fig. 3. 
Photograph 3. Part of a transverse section of a larger branch, at a more advanced 
stage ; seven of the vascular bundles (21 in all) are shown. Numerous layers 
of secondary wood have been formed. ‘The cortex is differentiated into two 
layers. C.N. 118*. x about 25. See also Plate 78, figs. 12, 13, and 14. 
Photograph 4. Radial section of part of a decorticated branch, showing two nodes, 
with their diaphragms. There is a considerable zone of secondary wood. 
Above the upper node, on the right hand, part of the base of a branch is 
shown. C.N. 1937. x about 9. From Mr. W1xp’s specimen. 
Photograph 5. Tangential section through the wood of an advanced stem. The 
section passed through the inner part of the secondary wood. Five outgoing 
foliar bundles are seen in transverse section, as well as two branches out 
of the four which the complete section shows at this node. Observe that 
there is no regular alternation of the vascular bundles above and below the 
node. Observe the small-celled tissue of the medullary rays below the node. 
C.N. 130*. x about 12. 
Photograph 6. Similar section of another specimen. This section has passed some- 
what further towards the exterior. Several foliar bundles are shown, and one 
branch. Observe that its connection with the trachez of the main stem is 
chiefly from below. C.N. 1554. X about 12. 
PLATE 73. 
Photographs 7, 8, and 9. Calamites. 
Photograph 7. Transverse section of Mr. Wrip’s specimen, at some distance from 
the base of the branch, showing typical Calamitean structure, with a large 
pith-cavity, and 24 bundles, each with its canal. C.N. 1941. x about 10. 
Photograph 8. Another section of the same, nearer the base. Pith-cavity much 
smaller, bundles normal, but only 14 in number. C.N. 1934. x about 10. 
Photograph 9. Third section of the same, taken close to the base. Pith of minute 
size, with small irregular cavity, probably of post-mortem origin. Only 10 
bundles, very crowded together, and with no distinct canals. C.N. 1933a, 
x about 10. ; 
Photographs 10-13. Calamostachys Binneyana. 
Photograph 10. Part of a radial section through a large strobilus. There are 18 
whorls of bracts in the specimen, of which 4 are shown. Between them are 
