DR. J. D. HOOKER ON WELWITSCHIA. 47 
Fig. 8. Transverse section of the root of fig. 5, of the natural size, showing great confusion of the wood- 
wedges. 
Fig. 9. Transverse section of root of fig. 7, of the natural size, and showing two medullary axes. 
Prate XII. Tissues of the stock, &c. (p. 10). 
Fig. 1. Parenchyma of the stock, including vessels, liber-cells, and sclerogen-cells covered with crystals. 
Magnified 60 diams. 
Fig. 2. Periderm of stock in longitudinal section, consisting of transversely elongated parenchyma and 
spicular cells. 
Fig. 3. Epidermis and subjacent cellular tissue of periderm near the leaf-base. Magnified 400 diams. 
4. Vessel from the peduncle, showing that the narrow spiral bands are spaces between the secondary 
deposits. Magnified 400 diams. 
Fig. 
Fig.5. Portion of a spicular sclerogen-cell, covered with crystals. Magnified 240 diams. 
6. Smaller portion of ditto, magnified 430 diams., showing crystals of two forms. 
7. Transverse section of a very large spicular cell, enclosed in parenchyma. Magnified 240 diams. 
8. A thin-walled spicular cell, with the crystals very small. Magnified 60 diams. 
Fig. 
Fig. 
Figs. 9 & 10. Small, branched spicular cells, with secondary deposits. Magnified 60 diams. 
. 11. Section of a small portion of another, after boiling in caustic potash. Magnified 60 diams. 
ig. 12. Branched liber-cell of very irregular diameter and unusual form. Magnified 240 diams, 
ig. 13. Portion of a liber-cell of the ordinary form, with transverse striae. Magnified 240 diams. 
. 14. Parenchyma of stock, becoming colloid. Magnified 240 diams. 
. 15. The same, involving a spicular cell with crystals. 
Fig. 
16. Transverse section of the parenchyma and vascular bundles of the roots, showing, to the left, 
liber-bundles, to the right, barred vessels, to the extreme right, spicular sclerogen-cells with 
crystals. Magnified 60 diams. 
Puate XIII. 
. 1. Portion of rachis of cone, with scale i» situ, showing the disposition of its vascular bundles. 
Magnified 2 diams. (see p. 25). 
«ded. 
05 d dy d da 
Fig. 2. The same, with the scale removed, showing the relation of the vascular bundles to the perianth. 
. 3. Transverse section of rachis of cone. Magnified 2 diams. 
. 4. Pitted cellular tissue from the same. Magnified 60 diams. 
. 5. The same, showing the obliquity of the pits. Magnified 240 diams. 
. 6. Longitudinal section through the base of a cone and peduncle, taken through the centre; of the 
natural size. 
. 7. The same section, taken close to the periphery, showing the anastomoses of the bundles. 
. 8. Transverse section of the peduncle, showing the irregular arrangement of the vascular bundles. 
Magnified 2 diams. 
. 9. Transverse section of pitted parenchyma of central part of peduncles, with a few liber-cells. 
Magnified 240 diams. 
. 10. Longitudinal section of the same, with portion of a vascular bundle. Magnified 240 diams. 
. 11. Transverse section taken through the peduncle, showing the isolated vascular bundles and 
scattered liber-cells. 
12. Transverse section of a quadrant of a root, magnified 2} diams., showing the form and disposition 
of the wedges and isolated bundles, 
Fig. 
