86 Seward. — Knowledge of Ly gin o dew dr on. 
Fig. 2 Longitudinal section (radial) showing the characteristic appearance 
of the wood as seen in radial section, and the imperfectly preserved tissues of 
the large pith. (Figs. 102 are from photographs by Mr. Gepp, and represent 
approximately the natural size of the sections.) 
Fig. 3. Portion of a transverse section of the centrifugal wood, with the broad 
medullary rays especially distinct at the lower end of the figure (from a photograph 
by Mr. Hayles of the Cavendish Laboratory, Cambridge), x 17. 
Fig. 4. Portion of the wood of Fig. 3 more highly magnified, showing the 
broad medullary rays, x 52. 
Fig. 5. Radial wall of a tracheid of the centrifugal wood. X320. 
Fig. 6. The inner edge of the wood and the pith-parenchyma: t, i', t" = leaf- 
trace-bundles, ^ — centripetal wood, s = sclerous nests (natural size). 
Figs. 7, 8. Tangential and radial longitudinal sections through the centrifugal 
wood. X52. 
PLATE VI. 
Fig. 9. Transverse section showing the inner termination of the centrifugal 
wood (^r 1 ), and the imperfectly preserved bands of centripetal tracheids (^ 2 ), and 
medullary rays. X52. 
Fig. 10. Transverse section showing the characteristic tapered rows of tracheids 
at the internal limit of the centrifugal wood, separated by spaces left on decay 
of the broad medullary rays: x 1 = centripetal xylern, s = sclerous nests (slightly 
enlarged). 
Fig. 11. Tangential longitudinal section passing through the centrifugal wood 
in the immediate neighbourhood of a leaf-trace-bundle. The figure represents only 
a portion of the outgoing trace. 
Fig. 12. Transverse section showing the inner ends of centrifugal tracheids and 
the outer limit of centripetal tracheids. x 52. 
Fig. 13. Lyginodendron anomalum. Transverse section, x 52. 
Fig. 14. Lyginodendron robustum. Slightly enlarged sketch of the inner edge 
of the xylem and the peripheral tissues of the pith ; p = radially-arranged secondary 
parenchyma, c = meristem ; x 1 = centrifugal, and x 2 — centripetal xylem ; s = sclerous 
nests. 
Fig. 15. Transverse section including a leaf-trace-bundle cut across somewhat 
obliquely, * = space at proximal end of the leaf-trace (slightly enlarged). 
Fig. 16. Transverse section to show the fairly well preserved centripetal 
xylem (j? 2 ). X52. 
