94 PLANT LIFE 
(Figs. 134 and B). A fairly young stem cut 
across and examined under a moderate magni- 
fication shows that the centre is occupied by 
a bulky pith around which are seen the cut 
ends of the conducting strands—the vascular 
bundles. Just outside these are to be found 
the cut ends of small rod-like strands of tissue, 
the sclerenchyma. These run down the stem, 
following, roughly, the course of the vascular 
bundles. They are connected laterally at 
intervals, and especially at a node where a 
leaf springs from the stem. Each of these 
sclerenchymatous strands consists of very 
much elongated cells with pointed ends that 
grow and insert themselves between their 
neighbours above and below, thus giving the 
rod or strand of sclerenchyma as a whole a 
considerable degree of tenacity. 
The walls of the cells become greatly 
thickened,:and the rod is sharply marked off 
from the soft tissues of the rind in which it 
is embedded. Regarded from the point of 
view of its physical properties it exhibits 
remarkablastrength. It is quite elastic even 
when submitted to considerable stress. This 
means that within certain limits it can be 
pulled out (z.e. elongated) by applying a 
force, and when this is withdrawn it will 
recover, and contract to its former length. 
In this respect the sclerenchymatous strands 
of many plants are but little inferior to good 
steel, and a strand one millimeter in cross 
section will stand a pull of about twenty 
