676 DR R. KIDSTON AND PROF. W. H. LANG ON OLD RED SANDSTONE PLANTS 
Fig. 15. Portion of clear peat, including above an obliquely longitudinal section of a rhizome of moderate 
size, and below a transverse section of the transition region to the shoot. The latter, on the left, has a well- 
preserved epidermis, and bears small scale-leaves. A small intrusive root-like rhizome is enclosed in its 
cortex below, x 14. (No. 2470.) 
Fig. 16. Longitudinal section of an axis. with indications of small scale-leaves (sc. 1.) and of leaf-traces 
( l.t .), but with structure closely similar to that of a large rhizome, ep., epidermis ; o.c., outer cortex ; 
i.c., inner cortex; ph., phloem; x., xylem. x 14. (No. 2439.) 
Plate HI. 
Fig. 17 Transverse section of an axis of the transition region showing hardly any advance on the structure 
of the rhizome. The stele has given off a smaller branch. x 14. (No. 2469.) 
Fig. 18. Transverse section of a more advanced phase of the transition from the rhizome to the leafy 
shoot. Small scale-leaves are borne on the surface, and the xylem is angled but not giving off leaf-traces, 
x 14. (No. 2471.) 
Fig. 19. Transverse section of a specimen of the transition region bearing small scale-leaves. Two steles 
are enclosed in the common cortex, preliminary to branching. The xylem is stellate and giving off leaf-traces, 
x 14. (No. 2456.) 
Fig. 20. Transverse section from the same axis as fig. 17, showing all the tissues of the early transition 
region, ep., epidermis ; o.c., outer cortex ; i.c., inner cortex permeated with fungus ; ph. phloem ; a:., "xylem. 
x 33. (No. 2472.) 
Fig. 21. Portion of fig. 19 more highly magnified, showing the stellate xylem (a;.), the distribution of the 
well-preserved phloem (ph.), and a leaf-trace ( l.t .) in the cortex, with xylem surrounded;-; by phloem, x 33. 
(No. 2456.) 
Fig. 22. Portion of fig. 16 more highly magnified, ep. epidermis; ox., outer cortex; i.c., inner cortex 
with fungus; ph., phloem ; x., xylem. x 33. (No. 2439.) 
Fig. 23. Scale-leaf from the transition region. x 60. (No. 2473.) 
Fig. 24. Transverse section of an advanced stage in tile transition region, with small scale-leaves and 
simple cortex, but with a stele like that of the larger leafy shoots, x 14; (No. 2473.) 
Plate IY. 
Fig. 25. Transverse section of two axes, separating in branching, with the structure of an early^stage 
of the transition region. Above is another more advanced example, the quadrangular xylem of which is giving 
off leaf-traces. x 14. (No. 2474.) 
Fig. 26. Transverse section of small root-like rhizome, ox., outer cortex; ix., inner cortex; ph., phloem ; 
x., xylem. x 60. (No. 2475.) 
Fig. 27. Transverse section of another small root-like rhizome with the epidermis (ep.) preserved, 
x 60. (No. 2476.) 
Fig. 28. Portion of clear peat showing two transverse sections of smaller!) izomes. The one on the left 
shows the epidermis well preserved on one side, x 33. (No. 2477.) 
Fig. 29. Transverse section of small rhizome, o.c., outer cortex ; ix., inner cortex ; ph., phloem ; 
x., xylem. x 60. (No. 2476.) 
Fig. 30. Transverse section of small leafy shoot. x 14. (No. 2479.) 
Fig. 31. Longitudinal section of a large leafy shoot showing two leaves attached to the stem. The dark 
bodies in the inner cortex are fungi, x 14. (No. 2476.) 
Plate Y. 
Fig. 32. Tangential section of leafy shoot showing two leaves in longitudinal section, that on the left 
attached to the stem. x 14. (No. 2471.) 
Fig. 33. Transverse section of medium-sized stem showing the leaves as they separate from the leaf-bases, 
x 20. (No. 2480.) 
