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. This is the 

 root-cap, which is a thimble-shaped sheath of looser cells 



per 



FIG. 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, phloem ; x, xylem. C. A portion still more highly magnified : 

 j)h, phloem ; p t 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 



