SHOWING STRUCTURE, FROM THE RHYNIE CHERT BED, ABERDEENSHIRE. 677 
Figs. 34, 35. Two successive tangential sections of a shoot showing the termination of a leaf-trace in the 
leaf- base, the attachment of the leaf and its free portion. x 14. (Fig. 34, No. 2481 ; Fig. 35, No. 2482.) 
Fig. 36. Transverse section of one-half of a bud-like grouping of leaves, the other half being lost by the 
brecciation of the chert, x 33. (No. 2483.) 
Fig. 37. Free portions of a number of well-preserved leaves in transverse section. x 33. (No. 2484.) 
Fig. 38. Complete leaf in longitudinal section, x 20. (No. 2456.) 
Fig. 39. Portion of the leaf in fig. 38 showing the papillate epidermal cells. x 60. (No. 2456.) 
Fig. 40. Longitudinal view of a number of leaves in a section of the chert, showing stomata ( st .) in 
surface view. x 105. (No. 2465.) 
Plate VI. 
Fig. 41. Transverse section of large stem, o.c., outer cortex; i.c.o., outer zone of inner cortex ; i.c.m., 
middle (trabecular) zone of inner cortex; i.c.i., inner zone of inner cortex; ph., decayed phloem; x., xylem- 
x 14. (No. 2464.) 
Fig. 42. Transverse section of stem, in which the outer cortex and the leaf-bases are prominent owing 
to the dark cell contents. x 14. (No. 2485.) 
Fig. 43. Transverse section of stem, o.c., outer cortex; i.c.m., trabecular middle zone of inner cortex; 
i.c.i., inner zone of inner cortex; ph., decayed phloem ; x., xylem ; l.t., leaf-traces in the neighbourhood of the 
stele and in the outer cortex. x 14. (No. 2490.) 
Fig. 44. Transverse section of a moderate-sized stem showing the corresponding arrangement of tissues, 
x 14. (No. 2491.) 
Fig. 45. Transverse section of moderate sized stem with more massive stellate xylem than that in the 
preceding figure, o.c., outer cortex; i.c.o., outer zone of inner cortex; i.c.m., middle trabecular zone of inner 
cortex ; i.c.i., inner zone of inner cortex. x 14. (No. 2492.) 
Fig. 46. Transverse section of small stem ; leaves in transverse section occur in the peat around. x 14. 
(No. 2468.) 
Fig. 47. Transverse section of small stem with well-marked trabecular zone of the inner cortex and 
three-rayed xylem. In the peat, on the right, are small twigs with imperfectly-preserved cortex, giving 
the appearance of dichotomous branching and of a cylindrical strand of xylem. x 14. (No. 2493.) 
Fig. 48. Group of small twigs with imperfectly preserved cortex in transverse section. x 14. 
(No. 2466.) 
Plate VII. 
Fig. 49. Obliquely transverse section of a stem with distinct outer cortex (o.c.) and uniform inner cortex 
(i.c.). Large traces, one apparently for a branch and the other for a leaf, are departing from the stele, 
x 14. (No. 2486.) 
Fig. 50. Transverse section of the . stele of the stem shown in fig. 47. ph., well-preserved phloem ; 
x., xylem. x 60. (No. 2493.) 
Fig. 51. Transverse section of stele in which the phloem extends right across, separating the xylem 
into distinct groups. x 60. (No. 2487.) 
Fig. 52. Transverse section of stele in which the imperfection of the central region of the xylem has led 
to the partial separation of the numerous enlarged ends of the rays. x 33. (No. 2472.) 
Fig. 53. Transverse section of stele with massive four-rayed xylem (x.) and partially-preserved phloem 
(ph.). l.t., leaf-traces. x 33. (No. 2488.) 
Fig. 54. Transverse sections of two small stems with the well-preserved xylem giving off leaf-traces 
enclosed by the cortex in which all trace of the tissues has disappeared. x 20. (No. 2449.) 
Fig. 55. Transverse section of xylem with leaf-traces departing from the enlarged ends of the rays.. 
x 33. (No. 2462.) 
Fig. 56. Transverse section of xylem showing the position of the groups of immersed protoxylem and the- 
arrangement of the departing leaf-traces. x 33. (No. 2489.)* 
Fig. 57. Transverse section of the stele of the stem in fig. 44 showing the departure and arrangement 
of the small leaf-traces. x 60. (No. 2491.) 
* In this and the preceding figure the soft tissues have been lost in the photograph in bringing out the details 
of the xylem. 
