“ PLANT TISSUES 119 
deposited on the walls of the sclerenchyma fibers.) When 
sclerenchyma is composed of cells which are more or less iso- 
diametric or moderately elongated, with thickened, lignified 
| ae? Si (PERE pp 
Fic. 60.—Stone cells from various sources. 1, From olive pit; 2, from cocoa- 
nut endocarp; 3, from flesh of pear; 4, from aconite root; 5, from capsicum; 6, 
from hazelnut; 7, from allspice. (Drawing by Hoffstein.) 
walls and conspicuous pores, its elements are called STONE 
Cets. Stone cells are distributed in fruits, seeds and barks 
of many plants, rarely in woods. They occur singly or in small 
groups or large masses. ‘They have been found forming the 
