72 THE JOURNAL OF INDIAN BOTANY. 



Cells with crystal sand occur in medullary rays and outer soft bast of 

 S. incanum and L. barbarian. Crystal sand occurs abundantly in 

 cortex and inner soft bast of S. incanum. The abundance of oxalate 

 of lime in the leaf and axis gives an acrid taste to the tissues of the 

 plants and prevents them from being easily devoured by animals. 



Veins are embedded and are not provided with bundle-sheaths. 



The hairy covering consists of clothing and glandular hairs. The 

 clothing hairs on the leaf and axis of both the species of Solatium 

 are tufted. They consist, in S. albicaule, of a short biseriate stalk 

 and of a tuft'of ray-cells, some of the rays being uniseriate (fig. 236). 

 In S. incanum (fig. 242), the stalk is multiseriate and is usually longer 

 on the axis. In addition to the tufted hairs in <S. albicaule, there 

 are uniseriate trichomes (fig. 238). Clothing hairs are absent in L. 

 bar bar um. 



Glandular hairs occur in leaf and axis of L. barbarian and of both 

 the species of Solanum ; and are composed of a short uniseriate stalk 

 and of an ellipsoidal head which is irregularly divided (fig. 237). 



Structure of the Axis. — The epidermis consists of a single layer of 

 tabular cells with the outer walls greatly thickened and convexly 

 arched outwards in S. incanum and L- barbarian. The epidermis in 

 S. albicaule is composed of more than one layer (three layers in the 

 specimen examined) of vertically tabular cells which are uniformly 

 thickened a little on all sides. The epidermal cells of L. barbarian 

 are mostly filled with crystal sand. The cortex in S. incanum, and 

 L. barbarian is characterised by cork which is subepidermal. Cork 

 in L. barbarian is strengthened by isolated stone-cells. The collen- 

 chyma is subepidermal as in S. albicaule, or it occurs below the 

 cork as in other members. In <S. incanum collenchyma is extensive 

 and the inner portion of the cortex consist of large polygonal cells, 

 some of which are filled with crystal sand. 



The pericycle forms a loose ring of bast fibres in both the species 

 of Solanuvi. Scleranchymatous pericycle is '■ not developed in L. 

 barbarian. 



The wood is composite in all members. Medullary rays are 

 uniseriate and numerous. The vessels are few and large and are 

 uniformly distributed in rows in the wood ring of S. albicaule and 

 L. barbarian ; interfascicular wood prosenchyma is extensive and con- 

 sists of cells with thickened walls and with small lumen. In 

 S. incanum the vessels are large and are arranged in bundles which 

 are connected by strands of interfascicular wood prosenchyma, formed 

 of cells with thin walls and large lumen. The wood-ring in 

 S. incanum is narrowed in a small portion on one side where it con- 

 sists of a few vessels and of extensive connecting strands of interfasci- 



