SPHAGNUM MOSS NICHOLS. 



227 



the absorbing cells is punctured toward the outside by several 

 bi Unite pores (fig. 2). It is through these pores that liquids are 

 sucked into the cells. Each cell, acting independently, sucks in 

 whatever liquid it comes in contact with until it is full. A sphag- 

 num plant, with its hundreds of leaves, each leaf containing hun- 

 dreds of these tiny absorbing cells, represents a highly efficient ab- 

 sorbing system. And this absorptive ability is not confined to plants 

 that are fresh; a dry, dead leaf is quite as efficient, when it comes 

 to taking up liquids, as a fresh one. This is due to the second 

 structural peculiarity of the absorbing cells; for inside of each 



DJAGTxMMT/C 



SURFACE AND SECTIONAL 



VIBWS OF 



/» S/V>ALL TOTZTION OT 



A SPHAGNUM 1EAT 



(-HIQHLY MAQNIFIEP) 



H:LftRQ£, COLORLESS 

 CELLS, T>EAT>, WITH 

 Outer walls per; 

 FoKATfo (p = pores), 



AND WITH SPIRAL 

 BANDS OF TH'CKfN- 

 ""G (T). 



G: SfaALL , QREEN 

 CELLS, LIVING, AND 



forming A werwo"RK 



WHICH ENMESHES- 

 THE COLORLESS 

 CELLS. 



CROSS. SECTION 



Fig. 2. 



one of these cells there is a spiral, spring-like coil of thickening (or 

 commonly a series of hoop-like ribs of thickening) which presses 

 outward, as it were, against the walls of the cell and serves to keep it 

 from collapsing. Even after a leaf has become completely dried out, 

 this " framework " serves to keep the cell cavity open. 



Incidentally, while it is the leaves which are most efficient in 

 the absorption of liquids, in some varieties of sphagnum both the 

 stem and branches are enveloped by one or more layers of absorbing 

 cells, essentially similar to those found in the leaves. 



It now becomes perfectly clear why it is that sphagnum is so 

 much superior to cotton as an absorbent. In cotton, liquids, for the 



