44 DR. J. D. HOOKER ON WELWITSCHIA. 
Fig. 12. Perianth more advanced, with immature ovule. 
Fig. 13. Perianth at the stage where it assumes its intermediate or oblong form. 
Fig. 14. Perianth still further advanced, and becoming orbicular. 
Figs. 15 & 16. Ovules of different forms from figs. 13 & 14. 
ig. 17. Longitudinal section of body of ovule, showing a very large embryo-sac. 
Fig. 18. An embryo-sac of unusual broadly transverse-oblong form. 
Fig. 19. Front and (fig. 20) back views of two scales from different parts of a female cone. 
Fig. 21. Membranous margins of the scale, showing the course of the liber-cells. 
Fig. 22. Small portion of ditto, showing the individual liber-cells running towards the margin, and ter- 
minating within it, in blunt apices. . 
Fig. 23. Epidermis from inner surface of coriaceous green part of a scale. 
Fig. 24. Epidermis from membranous outer part of a scale, showing the liber-cells. 
Fig. 25. Portion of a liber-cell, showing its transverse striation. ; 
Fig. 26. Epidermis of central area of scale, with liber-cells and spicular cells. 
Fig. 27. Spicular cells, with minute points on their surface, from the coriaceous part of the scale. 
Fig. 28. Lowermost free, but empty, scales of cone. 
Fig. 29. Lowermost connate (empty) scales of cone. 
(All these figures, but 1, 2, & 3, more or less magnified.) 
Puate IX. Development of female flower (p. 25) and embryogeny (p. 31). 
Chiefly from Mr. Baines’s specimens. 
Fig. 1. Uppermost imperfectly developed scale of cone, with naked nucleus of ovule at its base. 
Fig. 2. Another, more advanced, the nucleus surrounded with a thickened ring. 
Fig. 3. Very young ovule from the same. 
Fig. 4. Ovule with the thickened ring, which becomes the perianth. 
5. More advanced flower, the perianth supporting the still exposed nucleus, girt by another ring 
(its integument). 
Fig. 6. Flower still further advanced, the perianth having risen to a level with the ovule. 
Fig. 7. Flower further advanced, the perianth becoming 2-lipped. 
Fig. 8. The perianth much more advanced, in its urceolar compressed stage ; the ovular integument pro- 
duced far above the nucleus. 
Fig. 9. Longitudinal section of the same. 
Fig. 10. Perianth in its oblong condition (of the natural size). 
Figs. 11 & 12. Ovule and longitudinal section of the same, showing the embryo-sac and the two vascular 
bundles beneath the nucleus. 
Fig. 13. Perianth at a much later period, from which the ovule, fig. 15, was taken (of the natural size). 
Figs. 14 & 15. Ovules from the perianths, figs. 10 & 13. 
Fig. 16. Ovule with the outer integument carried up halfway, and the embryo-sac descending. 
Fig. 17. Ovule advanced still further, when the vascular bundles are developed on its walls. 
Fig. 18. Ovule at a still later stage of development, but much shrivelled, the growth of the endosperm 
not appearing to have advanced with that of the nucleus and its cone. 
Fig. 19. Longitudinal section of ditto, showing the loose embryo-sac loosely investing the tongue-shaped 
endosperm-mass. The dark lines have appeared in the cone above it. 
Figs. 20-24. Transverse sections of the cone of a nucleus, after the canals are fully formed in its substance. 
Fig. 25. Àn endosperm-mass apparently in an arrested condition, lying on a portion of the embryo-sac. 
Fig. 26. Cone of a nucleus removed, showing the rudimentary embryos continuous by their suspensors 
with the tubular terminations of the secondary embryo-sacs. 
