44 XEROPHYTIC NATIVE GRASSES, 



The epidermal cells (B.) in the depressions are very large, and, 

 although not distinctly bulliform in character, by their position 

 and arrangement probably aid in the rolling of the leaf. The 

 stomata are numerous, and invariably occur on the sides of the 

 depressions. They are themselves sunk, being bounded by 

 epidermal cells similar to those on the ventral surface. In the 

 rolled-up position of the leaf, these stomata would be completely 

 concealed. 



There are two kinds of bundles, viz., those (M.B^) in the 

 narrow bands, closed, and not bounded by hypoderma; and those 

 (M.B2) in the wider bands, also closed, but bounded on the 

 ventral surface by hypoderma. The smaller bundles (M.B3) are 

 completely surrounded by chlorophyll-bearing parenchyma, and 

 contain no xylem-elements. The larger bundles (M.B.^) are 

 similar in character. They are oval-shaped, and completely 

 surrounded by chlorophyll-bearing parenchyma. The phloem 

 does not present any noteworthy features. The xylem, however, 

 is characteristic in nature. All the vessels are extremely large, 

 much larger than in any other grass examined, more or less 

 uniform in size, and with very narrow lumens. 



Between the epidermis of the dorsal face and the larger 

 bundles are three to four rows of large, uncoloured parenchyma- 

 cells, probably functioning as water-storage cells. 



Coiiclusio7i. — The large, uncoloured parenchyma-cells, the ex- 

 tremely large xylem-elements, the depressed stomata, the narrow- 

 lumened epidermal cells, the intensely hairy surfaces, all aid in the 

 storage of water; to this purpose, the development of hypoderma 

 (stereome; seems to be sacrificed. 



^ote. —The presence of hairs, which are extremely numerous, 

 is not indicated in the diagram. 



Explanation of References. 

 H., Hypoderma — P., Phloem — X., Xylem — C.P., Chlorophyll-bearing 

 parenchyma — B., Bulliform cells— M.S., Mestome-sheath — St., Stoma — 

 U.P. , Uncoloured parenchyma— M.Bj, Primary bundle — M.Bj, Special 

 form of secondary bundle — M.Bj, Secondary bundle — M.B^, Intermediate 

 type of bundle — S.p.P. , Sub-papillose protuberance — T. , Trichome — V.S., 

 Ventral surface — D.S., Dorsal surface. 



