ROOT 107 



derived, is represented at the apex by a single initial layer of 

 cells. 



4. Outside the dermatogen, at the apex of the root, will be 

 found another formative tissue, the cells of which divide parallel 

 to the surface of the dermatogen : this is the calyptrogen-layer, 

 which is formative of the tissues of the root-cap. The latter 

 appears as a mass of parenchyma, covering the whole apex of 

 the root : the outer cells of it will be seen to be undergoing 

 mucilaginous degeneration of the cell-walls. 



