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PLANTS OF THE SOTOL REGION 625 
to the one above, and with two openings, this time fore-and-aft, 
and so alternating with the upper (/ 2). This inner arrangement 
is as if one were to take a rubber funnel and pinch the sides to- 
gether midway (/ 4, 7, /), leaving the margins otherwise flaring 
Fic. 4. Transverse section through superficial portion of leaf of Agave Lecheguilla. 
eu, cuticular layer of epidermis; c./., the cellulose layer; /, cell-lumen; /, f, rim 
of stomatal pit, which becomes a prominent projection above /”—the fore-and-aft 
Projections seen in f. 7; f, f, section of the inner projection with free margin at /” , 
the narrow median slit opening below into the still-air chamber, sc, which has wider 
communication through sc’ (compare f 2) ; as, assimilation tissue ; 7, the large, sub- 
Stomatal air-chamber. 
(4.4, f'). Below the slit-like neck then, the tube of the funnel 
‘should expand bulb-like, thus representing the still-air space im- 
mediately over the guard-cell apparatus (/. 4, 5¢). Monttestly : 
Such a device is well calculated to hinder direct communication 
