WHAT PLANTS ARE) MADE) OF 
51 
twists itself into roots, and the roots taper out to sen¬ 
sitive ends with delicate root-hairs growing along their 
sides. It needs a tender surface to drink in the sun¬ 
light; the gnarled, sturdy branches could not do this, 
so they learned to narrow their ends into slender twigs, 
and the twigs shaped themselves into leaves, flat and 
thin as paper and green with the sun-drinking fluid they 
contain. 
And all this shaping and changing and twisting has just 
one aim in view; the welfare of the cells. Now you no 
longer wonder why the man with the microscope told us 
that if we wanted to know the tree we must, 
“Study the cell!” 
