Seward. — On the genus Myeloxylon (Brong.). 19 
EXPLANATION OF FIGURES IN 
PLATES I AND II. 
Illustrating Mr. Seward’s paper on Myeloxylon. 
(When not otherwise stated the figures are drawn with objective A, Zeiss.) 
Fig. 1. Transverse section of a vascular bundle and two canals, a = remains of 
phloem, s = sclerenchymatous cells. p = position of protoxylem. 
Fig. 2. Block of Limestone (Millstone Grit) with weathered ‘petiole’ of 
Myeloxylon. On the smooth surface at ^ is faintly indicated an oblique section 
of a smaller fragment. Actual size of specimen io cm. long and io cm. wide. 
Fig. 3. Transverse section, rather less than natural size, of the larger petiole 
shown in Fig. 2, and longitudinal section of a smaller fragment. The white 
patches in the matrix outside the plant are sections of Goniatites. 
(For the photographs from which Figs. 2 and 3 are taken, I am indebted to 
Mr. Barber.) 
Fig. 4. Section of one of the vascular bundles of the specimen represented 
in transverse section in Fig. 3. The xylem has been displaced. 
Fig. 5. Another bundle from the same specimen, p = protoxylem. 
Fig. 6. „ „ „ c = canal. 
Fig. 7. „ „ ,, At a the xylem is seen still at- 
tached to the parenchyma of the ground-tissue. 
Fig. 8. Piece of hypodermal tissue ; in the large transverse section of Fig. 3 
this appears as a black patch. 
Fig. 9. Transverse section of a vascular bundle from a smaller fragment of 
the Millstone Grit Myeloxylon. p = protoxylem. s — s = sclerenchymatous cells. 
c = canal. 
Fig. 10. A piece of the hypoderm and ground-tissue, with canals, from the 
same specimen as Fig. 9. b = tangentially elongated ‘epithelial cells’ of 
the canal. c = limiting lines of canal-contents. h — h = remnants of thick- 
walled hypodermal tissue. 
Fig. 11. Longitudinal section of the same specimen as Fig. 10. a and a! = thick- 
walled cells of the hypoderm. 
Fig. 12. Longitudinal section of a canal from the same specimen, showing the 
dark-coloured contents, &c. Letters same as in Fig. 10. (Objective D, Zeiss.) 
Fig. 13. A vascular bundle from the Binney specimen, showing well-preserved 
phloem. 
Fig. 14. Another bundle from the same specimen, p — protoxylem. s — s = in- 
distinct sclerenchymatous cells. 
Fig. 15. This bundle shows two patches of phloem, the result of fusion of 
two bundles. 
