206 Gibbs . — Bio-histological notes on some new Rhodesian pla.nts. 
Fig. 5. A fruiting bract. Mag. 
Fig. 6. A flower showing the three perianth segments alternating with the three stamens, and 
the triangular ovary. x 75. 
Fig. 7. A longitudinal section through the ovary, showing the erect anatropous ovule, x 75. 
PLATE XII. 
Fig. 8. Part of a transverse section of the rhizome of Fuirena Oedipus , showing the broad cortex 
with hypodermal sclerotic ribs, the endodermis reinforced by a zone of sclerotic cells, and the solid 
central cylinder with amphivasal fibro-vascular strands, more numerous towards the periphery, 
x no. 
Fig. 9. Part of a transverse section through the swollen basal internode, showing the prolifera- 
tion of cortical tissue for starch storage purposes, a peripheral ring of leaf-trace fibro-vascular 
bundles, an inner cortical ring, and the medullary bundles, which are connected by thin plates of 
parenchyma across the large air-canals of schizogenous origin of which the medulla is composed, 
x 65. 
Fig. 10. A radial longitudinal section through the basal internode, showing the insertion of the 
leaf-trace bundles on to the cortical bundles, the limits of the starch storage cortical tissue, and the 
medulla with its large air-spaces. x 16. 
Fig. 11. Half of the transverse section of the stem taken through the third internode from the 
base, showing the hypodermal ribs, cortical parenchyma reduced to two or three layers, which 
show starch contents where they pass over the cortical bundles, the latter alternating with lysigenous 
air-spaces, and a medulla identical in structure with that of the basal internode, x no. 
Fig. 12. Part of a transverse section of the leaf, showing the differentiation of the epidermal 
cells on the dorsal and ventral surfaces, the connexion of the water-sheath surrounding the vascular 
bundles of the epidermis, and the lysigenous air-spaces which replace the mesophyll tissue of the 
leaf, x 1 000. 
Fig. 13. Transverse section of half of the leaf, showing the stomata limited to the dorsal surface 
and the very large water-cells and unicellular trichomes on the ventral surface, x 75. 
Fig. 14. Part of a longitudinal section of the leaf, through an air- canal, showing the breaking 
down of the mesophyll tissue and the papillose outgrowth of the cuticle of the epidermis, x 1000. 
Fig. 14 A. Surface view of stoma. 
Fig. *15. Part of a transverse section through a developing leaf of Carex stellulata in the very 
youngest stage, showing the mesophyll tissue not yet broken down, x 1000. 
Fig. 15 A. Part of a longitudinal section of a very young leaf of Carex stellulata , showing the 
mesophyll tissue beginning to break down, x 1000. 
Fig. 16. Part of a transverse section through a fleshy radical leaf of Justicia elegantula , showing 
starch storage in its tissues, x 1000. 
Fig. 17. A transverse section through one of the laciniate teeth of a scale-leaf of Hesperantha 
matopensis, showing the lignified inner layers of parenchyma. 
