STUDIES OF THE DEVELOPMENT OF PEPEROMIA HISPIDULA 337 
EXPLANATION OF PLATES XXXVI-XXXVIII 
All figures are camera drawings and are from hand sections or microtome 
sections, except figures i, 2, 18 and 22. 
The magnification given in the description of each figure is that actually shown 
by the figure as printed on the plate. 
Abbreviations used: A, air chamber; As, archesporium; Ax, axis; Br, floral bract; 
Bs, bristle of fruit; C, carpel; Cp, chloroplast; D, nuclear disc; DAs, definitive arche- 
sporium; £, egg; Kd, endosperm; EdN, endosperm nucleus; Em, embryo; En, endo- 
dermis; F, fungus hyphae; FL, fore-leaf; H, hydathode; In, integument; L, leaf; 
Mp, micropyle; Nc, nucellus; No, nucleolus; Oc, oil-containing cell; Osp, oospore; 
P, perisperm; Pa, parietal layer; PG, pollen-grain; PI, phloem; PMC, pollen mother- 
cell; PPa, primary parietal layer; Pr, peripheral cell; S, stem, SF, spindle fibers; 
Sg, stigma; Sp, spike; St, stamen; Sy, synergid; Tp, tapetum; Tr, trichome; VB, 
vascular bundle; W, wing of stem or decurrent margin of petiole. 
Fig. I. Surface view (glycerine mount) of terminal portion of mature plant, 
showing stem, two spikes and the position and structure of leaves. X 23^. 
Fig. 2. Optical section (glycerine mount) of trichome on stem opposite base 
of leaf. X 117. 
Fig. 3. Part of vertical section of leaf, with multicellular trichome. X 117. 
Fig. 4. Longitudinal section of tip of primary root. X 117. 
Fig. 5, Part of longitudinal section of mature root, showing vascular bundle, 
crinkled endodermis and cortex. X 216. 
Fig. 6. Transverse section of mature root, showing vascular bundle, endodermis, 
root hairs, and fungus hyphae in cortex. X 117. 
Fig. 7. Part of radial section of root, showing penetration of cell walls of cortex 
by fungus hyphae. X 216. 
Fig. 8. Portion of similar section, showing a much swollen hypha. X 216. 
Fig. 9. Part of tangential section of root showing crinkled radial walls of endo- 
dermis. X 216. 
Fig. 10. Transverse section of stem. X 28. 
Fig. II. Transverse section of stele of stem. X 117. 
Fig. 12. Part of longitudinal section of young stem (peduncle), showing epi- 
dermis with oil cells and hydathodes. X 400. 
Fig. 13. Part of longitudinal section of mature stem, showing structure of cell 
wall of epidermis. X 340. 
Fig. 14. Transverse section of petiole. X 36. 
Fig. 15. Transverse section of median vascular bundle of petiole. X 252. 
Fig. 16. Part of transverse section of leaf including its midrib (glycerine 
mount). X 117. 
Fig. 17. Part of transverse section of leaf at margin (glycerine mount). X 117. 
Fig. 18. Part of lower surface of leaf, showing distribution of stomata, hyda- 
thodes and oil-cells, overlying water glands at apex of leaf (glycerine mount). X 1 17. 
Fig. 19. Surface view of typical stoma and its surrounding cells. X 216. 
Fig. 20. Transverse section of guard cells with cutinized margins (glycerine 
mount). X 400. 
Fig. 21. Longitudinal section of tip of leaf through gland at end of midrib. 
X 117. 
