Page:The Journal of Indian Botany.djvu/136

 Structure of the Axis .'—The epidermal cells are small and poly- gonal, with outer walls greatly thickened and convexly arched outwards. The cortex is characterised by subepidermal cork and by collenchyma. The assimilatory tissue is formed of chlorenchyma.

The pericycle in M. Denhamii is formed of an outer ring of groups of stone-cells and of an inner ring of radially elongated groups of bast fibres. The groups of stone-cells and of bast fibres are separated by colourless parenchyma. In M. magnifolia the pericycle is formed of a loose ring of groups of stone-cells.

The wood is composite and is much narrowed at two opposite points which probably represent the plane at right angles to that which is affected by the prevailing wind. The vessels in the broader portion are larger and less numerous. The wood in M. magnifolia is compo- site and is of uniform breadth. Interfascicular wood prosenchyma is extensive and is composed of cells with thick-walls and small lumina. Medullary rays in ill. Denhamii are 1-3 seriate, broadening outwards in the form of wedges between the groups of soft bast and are in contact with parenchymatous cells separating the groups of stone-cells and of bast fibres. Medullary rays in M. magnifolia are uniseriate.

The pith is distinguished by the occurrence of mucilage canals and is composed of thin-walled cells.

Grewia populifolia Vahl.— Front cavity placed in depres- sions formed by the thickened outer epidermal walls, Solitary crystals few and occurring near the veins and in the cortex. Veins vertically transcurrent above and below by sclerenchyma. Clothing hairs tufted. Glandular hairs club-shaped with the head divided by horizontal and vertical walls. Pericycle forming a composite ring of stone-cells. Medullary rays uniseriate.

Grewia villosa Willd. — Front cavity on a level wifch the surface. Solitary crystals numerous and occurring near the veins, in the cortex and pith. A few conglomerate crystals present near the veins. Veins vertically transcurrent above by sclerenchyma 'and below by bundle-sheath cells. Clothing hairs tufted. Glandular hairs club- shaped with the head divided by horizontal and vertical walls. Cork subepidermal with one or two layers of thickened and lignified cork- cells at its lower end. Pericycle formed of a composite ring of' stone-cells. Medullary rays 1-2 seriate.

Grewia abutilifolia Vent.— Figs. 63, 64. Front cavity on a level with the surface. Solitary crystals few and occurring near