Page:The Journal of Indian Botany.djvu/327

 the interior. The bundles are oonnected together by broad strips of ground tissue which resemble medullary rays. Bundles in the inner ring almost meet in the centre in Gitridlus Golocynthis and in Melothria maderaspatana. The vessels expecially those of the bundles of the inner ring have very wide lumina.

A few cells of soft bast on either side of the bundles hold tanni- niferous contents in all members etcept Momordica dioica.

The pith is greatly reduced on account of the bundles of the inner ring projecting inwards. It consists of a few thin-walled cells.

General Review. — The epidermal cells have outer walls a little thickened. The mesophyll is bifacial. Stomata are usually elevated above the epidermis, much more so on the axis where they are usually situated at the apex of pedestals formed by the subsidiary cells. The stomata, as a rule, are more numerous on the lower surface of the leaf. The hairy covering consists of uniseriate thin-walie I triohomes seated on subsidiary ceils which, on the axis, are raised above the base of the trichomes in the form of a pe lestal. The trichomas are some- what jointed and more numerous on the lower surface of the leaf. Internal secretory organs ate represented by a few isolated cells of soft bast with tanniniferous contents in all members except Alomor- dica dioica. The glandular hairs are placed in epidermal depressions and consist of a short uniseriabe stalk and of an oval head divider by horizontal and vertical walls. The pericycle forms a continuous and undulated ring of stone-cells or it is formed of closely placed groups of stone-sells. Gollenchyma is developed below the epidermis of the angles. The vascular bundles are bicollateral and are situated roughly in two rings. The bundles of the outer ring are much smaller and are situated below the angles; bundles belonging to the inner ring are much larger and are placed below the furrows; smaller and larger bundles project outwards and inwards respectively. The bundles are separated from one another by broad strips 01 ground tissue resembling medullary rays. The vessels have wide lumina and simple perforations. The pith is greatly reduced as the bundles of the inner ring almost meet in the centre.

Trianthema triquetra Bottl. & Wild.— Figs. 139, 140. Leaves fleshy. Mesophyll characterised by an extensive aqueous tissue. Stomata found only on the lower side of the leaf. Arcs of palisade cells on the lower side. Veins embedded and half enclosed with green bundle-sheaths. Clustered crystals found near the veins, in the cortex and in the pith. Some of the epidermal cells bladder-like and atte- nuated at the apices into hair-like structures, Axes angled, Wood