1030 Scott. — Structure of Mesoxylon Lomaxii and M. poroxyloides. 
Fig. 12. Lower end of right-hand bundle from Fig. 11 in slightly oblique tangential section. 
x 2 , centrifugal xylem of bundle; x.p., island of xylem-parenchyma ; px, protoxylem ; x, centripetal 
xylem. x 100. Slide 2358. 
Fig. 13. Longitudinal section through the middle region of the pith, showing the finer 
diaphragms, x 32. Slide 2356. Cf. PI. XC, Fig. 22. 
Fig. 14. Radial section through peripheral pith and wood, passing in places through a primary 
xylem-strand. p' , inner, p" , outer layer of pith ; x, primary xylem ; between p" and x a few 
elongated cells can be detected ; x 2 , secondary wood with medullary rays, x 38. Slide 2356. 
Fig. 15. Transverse section of wood, phloem, and pericycle. x 2 , secondary wood; ph , broad 
zone of phloem, mostly secondary ; s.s., ‘ secretory sacs ’ of pericycle. x 42. Slide 2352. 
Fig. 16. Tracheides of secondary wood, in radial section, showing pits, x about 160. 
Slide 2356. 
PLATE LXXXIX. 
Mesoxylon Lomaxii. 
From Drawings: Fig. 17 by Mr. G. T. G william, Figs. 18-21 by Miss G. C. Harrison. 
Fig. 17. General radial section of fragment of stem, pd , periderm or secondary cortex ; x, 
wood ; p, persistent zone of pith ; d.p., discoid pith, much broken, x 2^. Slide 2383. 
Fig. 1 8. Transverse section of a xylem-strand, after fusion, at the border of the pith, sh, 
bundle-sheath ; x, centripetal wood, some of the elements badly preserved ; px, probable protoxylem ; 
x 2 , centrifugal wood ; m.r., medullary ray. x about 150. Slide 2325. 
Fig. 19. Tangential section of secondary wood, m.r., medullary rays, of very varying length, 
x about 120. Slide 2377. 
Fig. 20. Tangential section of phloem, sd., probable sieve-tubes; m.r., medullary rays, 
x about 120. Slide 2377. 
Fig. 21. Tracheide from a radial section, showing three rows of bordered pits, x about 300. 
Slide 2383. 
PLATE XC. 
Mesoxylon poroxyloides. 
From Drawings : Fig. 22 by Mr. G. T. G william, Figs. 23 and 24 by Miss G. C. Harrison. 
Fig. 22. General approximately radial section, c, cortex; ph, phloem; x , wood; p, pith, 
showing the persistent outer zone and the coarser and finer diaphragms of the middle discoid 
portion, x about 3. Slide 2356. 
Fig. 23. Transverse section of a fused xylem-strand at the border of the pith, x, centripetal 
xylem; px, protoxylem ; x 2 , centrifugal xylem ; m.r., medullary rays, x about 200. Slide 2354. 
Fig. 24. Row of eight bundles (z >.b.) constituting a leaf-trace entering the base of a leaf. In the 
better-preserved bundles centripetal and centrifugal xylem can be distinguished, x 33. Slide 2352. 
The slide-numbers all refer to the Scott collection. 
