• PLANTS OP THE INDIAN DESERT. 227 



Larger veins vertically transcurrenfc. Upper and lower cells of sheaths 

 of vertically transcurrent veins aqueous. Sheaths complete round 

 the veins. Mechanical tissue in the leaf in the form of I-girders and 

 of isolated sub-epidermal girders on the lower side above smaller 

 veins. T. S. of the axis elliptical. Assimilatory tissue in the axis 

 chlorenchymatous. Mechanical tissue in the axis forming a stereome 

 tube supplemented by I-girders. Webs formed by unmixed small 

 vascular bundles. Smaller vascular bundles forming webs. Larger 

 vascular bundles in the medullary tissue, few and with arcs of 

 stereome on the outer side. Medullary tissue of thin-walled cells. 



Eleusine aristata Ehrenb.— Figs. 349, 350. Not grooved. 

 Epidermal cells on the lower surface vertically elongated and papillose. 

 Hairs short, unicelluler and bluntly pointed. Stomata more nume- 

 rous on the lower surface. Articulation tissue extending between the 

 surfaces. Palisade cells forming complete girders round smaller veins ; 

 veins provided with complete sheaths. Larger veins vertically trans- 

 current. Mechanical tissue forming I-girders supplemented by isolated 

 sub-epidermal girders on the lower side below smaller veins. Assimi- 

 latory tissue in the axis forming groups of palisade cells. Mechanical 

 tissue in the axis in the form of a stereome tubo supplemented by iso- 

 lated subepidermal girders alternating with I-girders. Webs formed by 

 unmixed vascular bundles. Larger vascular bundles in the medullary 

 tissue, few and with arcs of stereome on the outer side. Medullary 

 tissue of thin-walled cells. 



(To be continued.) 



