68 THE JOURNAL OF INDIAN BOTANY. 



bifacial leaves of C. glomeratus and /. sindica. Guard-cells are elevat- 

 ed in C. microphyllus (tig. 228), G. glomeratus and I- sindica 

 (figs. 231, 232); they are placed in the plane of surrounding cells in other 

 members. The guard-cells are accompanied by subsidiary cells except 

 *n C. cretica. The front cavity is on a level with the surface in 

 C. glomeratus and I. sindica (fig. 233) ; in other members it is placed 

 in a depression formed by thickened outer epidermal walls. The 

 elevated position of the guard-cells may be due to the occurrence of a 

 dense protective covering of clothing hairs. 



The mesophyll is isobilateral (fig. 228) in all members except 

 C. glomeratus and I. sindica (fig. 231), in which it consists of palisade 

 tissue on the adaxial side and of arm-palisade tissue on the abaxial side. 

 Internal secretory organs occur in the form of secretory cells in 

 the middle of the mesophyll of B. kitifolia and C. glomeratus and in 

 cortex and pith of I. sindica (fig. 234 G). In B. latifolia and G. glomer- 

 atus they consist of colourless secretory cells with surrounding arm- 

 palisade cells differentiated into subsidiary cells. Secretory cells in 

 /. sindica are greatly horizontally elongated and hold tanniniferous 

 oontents. 



Oxalate of lime occurs in the form of clustered crystals in the 

 neighbourhood of veins and in the cortex and pith, and in the form 

 of solitary crystals in the soft bast of B. latifolia. In other members 

 oxalate of lime is not found. 



The veins are embedded except some of the larger ones in B. lati- 

 folia which are vertically transcurrent above and below by collen. 

 chyma. The veins in G. cretica, B. latifolia and G. microphallus 

 (fig. 228) are provided with green bundle-sheaths. Vascular bundles 

 of the veins are bicollateral. 



Hairy covering consists of clothing and glandular hairs. Cloth- 

 ing hairs are composed of a terminal cell of variable shape and of a 

 stalk-cell seated either upon a single epidermal cell, or on two epider- 

 mal cells formed by a vertical wall (fig. 231), or on a multicellular 

 pedestal of epidermal cells (fig 235). 



The terminal cell is simple and is seated straight upon the stalk- 

 cell in C. glomeratus (fig. 230) or seated obliquely on the stalk-cell in 

 C, microphyllus (fig. 228). In 1. sindica the stalk-cell of clothing hairs 

 on the leaf is placed vertically on a single epidermal cell or on two 

 epidermal cells formed by a vertical division wall (fig. 231) ; the stalk- 

 cell on the axis is seated vertically on a multicellular pedestal of 

 epidermal cells (fig. 235). The terminal cell bears minute solid knobs 

 on the surface. 



In G. cretica (figs. 224, 225) and B. latifolia (fig. 226), the terminal 

 cell is two-armed ; arms are of uniequal length and are horizontally 



