x1] STONEWORTS, AND PEPPERWORTS. 171 
off a number of erect, tapering leaves from four 
to six inches in length. These leaves consist of four 
rows of long cells placed side by side, and subdivided 
by transverse partitions, It is these transverse parti- 
tions which show through the epidermis and give the 
leaf the jointed appearance shown in fig. 129. The 
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j 
J 
\ I Yy 
\ i f) f 
\ fi, if 1 
SQ 
| x : ih ff f 
NN HH 
Fic. 129. 
base of the leaf is very broad, and concave; within 
the hollow it bears the fructification, which is of two 
kinds. The spore-cases produced by the outer leaves 
contain large four-sided spores which open on the 
upper surface by three triangular valves; whilst those 
of the inner leaves are minute and more numerous. 
