98 THE JOURNAL OF INDIAN BOTANY. 



the form of bundles of acicular or rod-like crystals in the pith cells of 

 B. hochstetteri. Anamolous structures are represented by isolated 

 thick-walled vessels in the pith of B. hochstetteri. 



General Revieiu. — Epidermal cells have the outer walls thickened. 

 There are large cells, containing rounded cystoliths, intercalated 

 amongst ordinary epidermal cells. The stomata are accompanied by 

 subsidiary cells. Mesophyll is either isobilateral or is composed of 

 palisade tissue on the upper and of arm-palisade tissue on the lower 

 side. Structures resembling internal glands are found in the mesophyll 

 of some members. Oxalate of lime is found only in the pith cells of 

 B. hochstetteri, in the form of bundles of acicular or rod-like crystals. 

 Besides simple unicellular hairs or uniseriate trichomes which are of 

 general occurrence, there are special forms of trichomes such as 

 armed trichomes on the axis of B hochstetteri. External glands are 

 found in all members. The assimilatory tissue in the axis is com- 

 posed of chlorenchyma or of palisade cells. The collenchyma either 

 forms groups or is found in the form of a more or less continuous 

 ring, below the epidermis. An aqueous tissue is found in the leaf 

 and axis of B. sindica. Sclerenchymatous pericycle occurs only in 

 B. patula, in the form of isolated bast fibres. The wood forms a 

 composite ring. The interfascicular wood prosenchyma is fairly 

 extensive in members in which the vessels are not uniformly distri- 

 buted. The pith consists of thin-walled or thick-walled cells. 

 Anamolous structures are represented by thick-walled vessels in the 

 pith of B. hochstetteri. 



VERBENACEAE. 



Boucbea marrubifolia Schemer.— Figs. 260, 261, 262. PI. 

 XXVI. Epidermal cells tabular with outer walls very greatly thickened. 

 Guard-cells accompanied by two subsidiary cells. External glands 

 composed of a uniseriate stalk and of an elliposidal bicellular head. 

 T. S. of the axis quadrangular. Pericycle formed of groups of the 

 stone-cells. Cork absent. 



Cleredendron Phlomidis L./.— Figs. 263, 264. Epidermal 

 cells tabular with outer and inner wall equally a little thickened. 

 Guard-ceils accompanied by 4-5 ordinary epidermal cells. External 

 glands composed of a stalk-cell and of a broad elliptical head divided 

 by many vertical walls. Pericycle forming a loose ring of stone-cells. 

 Cork developed below collenchyma. T. S. of the axis circular. 



Structure of the Leaf. — The epidermal cells are tabular with the 

 outer and inner walls thickened, the thickening of the outer walls 

 being considerable in B. marrubifolia (fig. 260). The lateral walls 



