in vegetables, the bark or rind, principal of trees. This is to be conceived as consisting of a number of cylindric and concentric surfaces whose texture is reticular, and in some trees plainly extrudible every way, by reason that the fibres are soft and flexible. While in this condition, they are either hollow regular canals, or, if not so, they have interstitial spaces which serve the office of canals. The nutritious juice which they are continually receiving, remains in part in them, makes them grow in length and thickness, and strengthens and brings them closer together; and by this means the texture which was before reticular becomes an assemblage of straight fibres ranged vertically and parallel to each other; that is, as they are thus altered behind one another, they by degrees become a new substance, more woody, called bila.