72 THE JOURNAL OF INDIAN BOTANY. 



pericycle forming a loose ring of bast fibres. Oxalate of lime not 

 occurring in any form. 



Structure of the Leaf : — Epidermis in P. erioptera consists of 

 tabular cells with outer and inner walls arched convexly outwards 

 and inwards respectively. Outer walls are thickened ; lateral walls are 

 thin and straight. 



Stomata occur on both the surfaces of the leaf. The guard-cells 

 are surrounded by ordinary epidermal cells and are situated in the 

 plane of the surrounding cells (figs. 38, 41). The front cavity is 

 arched over by outer horns of the guard-cells, which are quite pro- 

 minent and come close together. The front cavity is placed in a 

 depression formed by the outer thickened walls of the epidermal 

 cells. Stomata on the axis (fig. 41) of both the species have the 

 same characters as those on the leaf of P. erioptera. The mesophyll 

 is composed of the palisade tissue on the upper side and of arm- 

 palisade tissue on the lower. There are numerous lysigenously 

 formed cavities in the arm-palisade tissue (fig. 38 L.C.) ; they may 

 occasionally serve for storing water. 



Oxalate of lime occurs in the form of clustered crystals near 

 the veins of the leaves and in the assimilatory tissue of the axis of P. 

 erioptera (figs. 38, 39). Besides the clustered crystals, there are 

 elongated compact bundles of diamond shaped bodies, in the palisade 

 tissue of the leaf ; these bundles are comb-like at their ends on 

 account of the projecting pointed ends of the diamond shaped bodies. 

 As regards composition of these bodies, I cannot say anything. 

 Oxalate of lime is not found in any form in P. irregularis. 



Veins are few and are embedded ; they are enclosed in bundle* 

 sheaths of thin-walled colourless cells. 



Hairy covering on the leaf and axis in both the species consists 

 of unicellular thin-walled clothing hairs, either straight or hooked, 

 and distinguished by knob-like thickenings on their walls. Glandular 

 hairs are not found. 



Structure of the Axis : — Epidermis is two-layered in P. erioptera 

 while it is single layered in P. irregularis. Epidermal cells are tabular 

 with outer-walls greatly thickened. Outer walls are convexly arched 

 outwards in P. irregularis. Cuticle is thick, especially so in P. eriop- 

 tera. Lateral walls are straight. The primary cortex functions as 

 the assimilatory tissue and is composed of chlorophyll containing 

 parenchyma in P. irregularis and of palisade tissue in P. erioptera. 

 Groups of stone-cells occur in the ribs. 



The pericycle is composed of a more or less continuous ring of 

 bast-fibres, which are thickened, straitified and have a narrow lumen 

 In P. erioptera. The ring is of uniform breadth in P. erioptera, while 



