SECT. IV. THE CORTICAL LAYERS. 327 



bark of young trees, or of the young parts of 

 aged trees, the apertures formed by the coincidence 

 of the meshes are not left empty but are occupied 

 by a pulp somewhat compressed, which traverses 

 the longitudinal fibres, and binds and cements them 

 together. The cortical layers therefore are com- Constitu- 

 posed of two elementary parts bundles of Ion- ent 1>arts ' 

 gitudinal fibres constituting a net-work and a mass 

 of pulp, more or less indurated, filling up the meshes. 



The inner layers are soft, smooth, and flexible, 

 and capable of subdivision till reduced to an abso- 

 lute film, but not always exhibiting a conspicuous 

 net-work, at least till macerated in water, or ex- 

 posed to the action of the atmosphere, which de- 

 composes and detaches the pulp or cellular tissue 

 without affecting the longitudinal fibre. 

 , The innermost of the layers is denominated the Li- Liber, 

 her, the Latin term for a book, from its having been 

 used by the ancients to write on before the inven- 

 tion of paper. It is the finest and most delicate of 

 them all, and often most beautifully reticulated. 

 But the Liber of Daphne Lagetto is remarkable 

 beyond that of all other plants for the beauty and 

 delicacy of its net- work, which is not inferior to that 

 of the finest lace, and at the same time so very soft 

 and flexible that in countries in which the tree is a 

 native the lace of the Liber is often made to supply 

 the place of a neckcloth.* 



But the layers of the bark do not always invari- Anoma- 

 ably constitute a net-work such as has now been ies ' 



* Sloane, HUtory of Jamaica, vol. ii. p. 22. 



