488 DR. ERIC DRABBLE ON THE 
EXPLANATION OF THE PLATES. 
PLATE 48, 
Fig. 1. Longitudinal section of stem of Kentia sp. showing origin of root. 
2. Diagram of do. 
3. More advanced apex of young root. 
4. Group of cells in cortex of stem, in front of advancing root-apex. (See text.) 
5. Longitudinal section through the common initial group in meristem of apex of Areca. 
6. Diagram of apex of root of Areca. 
Figs. 7-10. Transverse sections of apices of roots showing progressive changes in the procambial 
tissue. 
Fig. 11. Apex of root of Kentia sp. showing root-cap. 
PA & 5 Triartiasp. — ,, 9 
13. Longitudinal section taken a short distance above the apex of the root in Kentia, showing 
root-cap and “epidermis ” or limiting-layer extending below root-cap. 
14. Longitudinal section of root of Kentia sp. showing the very thick-walled cells of the root-cap 
and an irregularity in the limiting-layer. 
15. Transverse section of outer layers of root in Caryota ochlandra. 
16. Transverse section of outer layers of root in Phenix sylvestris, showing lignification 
proceeding both centripetally and centrifugally. 
17. Transverse section of outer layers of root in Dypsis madagascarensis. 
18. Development of air-space in Kentia sp. 
Figs. 19 & 20. Air-spaces in Kentia sp. 
Fig. 21. Air-spaces in Phytelephas macrocarpa. 
22. 5 Metroxylon Soo. 
23. Ze Triartia sp. 
24. e Licuala gracilis. 
Figs. 25-27. Development of thyloses in air-spaces of Areca Catechu. 
PLATE 49. 
Fig. 28. Air-spaces in Licuala spinosa. 
29. » Corypha australis. 
30. v Phenix sylvestris. 
31. Tracheids in fibrous bundle of young root of Dictyosperma album. 
32. Stegmata in Raphia Hookeri. 
33. Stone-cells in cortex of Sabal Palmetto in longitudinal section. 
34. Lignified elements in cortex of Livistona australis. : 
35. 5 $» Hyophorbe amaricaulis. 
96. Fibres in cortex of Kentia sp. 
87. » 5 Raphia Hookeri, with stegmata. 
Figs. 38-40. Development of crystal-sacs in Kentia sp. 
Mat 41. Crystal-sacs of Kentia sp. in transverse section. 
.42. Mucilage-cells in Caryota sp. 
SC EH Endodermis and pericycle in contractile rcot of Corypha umbraculifera (transveWe section). 
44 „ in longitudinal section. 
= 45, ees in Livistona oliveformis (transverse section). 
