224 The Botanical Gazette, [August, 



Bulliform cells forming smaller groups \ tj" p a i m eri. 



Stomates depressed, surmounted by epidermal expansions. ... U. Palmen. 



Mestome-bundles . 



One buudle between each group of bulliform cells and the in- 

 ferior epidermis U. latifoha. 



Leptome and hadrome surrounded by a sheath of thick-walled J »j' qJ^^ 



parenchyma in the large bundles j jr p a i me ri. 



( U. latifolia. 



Only the leptome surrounded by thick -walled cells j tt paniculata. 



Groups of thick-walled parenchyma in the leptome U. Palmen. 



Parenchyma sheath containing starch, extending from the su- 

 perior to the inferior epidermis, not forming any annular 



sheath around the bundle U. paniculata. 



Mesophyll. 



c * a u t i a u i U. paniculata. 



separated by groups of uncolored parenchyma -J tt p a l me ri. 



Stereo me. 



Six isolated groups on the superior face of the carene U. latifolia. 



One group opposite the bulliform cells * U. paniculata. 



Isolated groups inside the parenchyma-sheath U. paniculata 



Uncolored parenchyma. 



r\ i • .i ( U. latifolia. 



One large group in the carene \ y g raC ilis. 



^ ( U paniculata 



One group between the mestome bundles -J tt' p a i m eri. 



U. S. National Museum, Washington, D. C. 



Explanation of Plates. 



Plate XXL — Figs. 1-4. Uniola gracilis. — Fig. 1. Transverse section of leaf. 

 X 37.— Fig. 'I. Transverse section of the median part of the leaf, the carene; 

 the inferior face of the leaf at /. X 160.— Figs. 3 and 4. Transverse sections 

 of two small mestome-bundles. Fig. 3 shows a closed sheath of thick-walled 

 parenchyma-cells inside the proper parenchyma sheath P. L, the leptome: \ 

 the stereome on the inferior face of the leaf. In fig. 4 the inner sheath is not 

 complete, but merely represented by two groups of thick-walled cells. X 200. 



Fig. 5. U. Paimeri. Transverse section of a large mestome-bundle. On t 



On the 



left side in the figure are the bulliform cells to be seen at B, C, and the meso- 

 phyll at M. Several thick-walled parenchyma cells are to be observed in the 

 leptome and there is a closed sheath of similar cells inside the proper paren- 

 chyma-sheath P. X 320. 



Plate XXII. — Fig. 6. U. gracilis. Epidermis, taken from the carene, trans- 

 verse section. X 560. 



Fig. 7. r. ni/ida. Transverse section of leaf ; the inferior face at I. X ~ 4 

 Figs. 8-12. L . pamcuiata.—ing. 8. Transverse section of leaf; the inferior 

 face at /. X HO. Fig. 0. Transverse section of a large mestome-bundle. The 

 proper parenchyma-sheath, P, contains starch, figured in a few of the cells, as 



