THE SEEDLING AND YOUNG PLANT 25 
root would show a more or less loose sheath of cells in 
addition to and outside this piliferous layer. Thisis the 
root-cap, which is a thimble-shaped sheath of looser cells 
Fia. 5.—A. Transverse section of young root under a lens, showing 
the axis-cylinder, a; epidermis or piliferous layer, e; and the 
cortex between. B. The same more highly magnified: c, cortex; 
p, phloém; #, xylem. co. A portion still more highly magnified : 
ph, phloém; p, pith; per, pericycle; sh, sheath (endodermis) ; 
other letters as before. 
covering the tip of the root as a thimble covers the end 
of the finger, only we must imagine the extreme tip of 
the finger organically connected with the inside of the 
cap to make the analogy suitable (see fig. 6). The rest 
