OF TOREST-TREES.

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(as may be seen in any shoot of the first year) and after grow thicker, chap. m.being itself absumed, or converted into wood ; as it is certain cartilagesor gristles are into bones, (in the bodies of animals,) from which, to sense,they differ even as much as pith from wood.

These rings or spaces appearing upon transverse section, (as they appearelliptical upon oblique, and straight lines upon direct section,) are noother than the extremities of so many integuments, investing the wholetree, and, perhaps, all the boughs that are of the same age with any ofthem, or older.

The growth and augmentation of trees, in all dimensions, Is acquirednot only by accefsion of a new integument yearly, but' also by the recep-tion of nourishment into the pores and substance of the rest, upon whichthey also become thicker; not only those towards the middle, but alsothe rest, in a thriving tree: yet the principal growth is between the barkand body, by accefsion of a new integument yearly, as hath been men-tioned ; whence the cutting of the bark of any tree, or bough, roundabout, will certainly kill it.

The bark of a tree is distinguished into tings or integuments, no lefsthan the wood, though much smaller or thinner, and therefore not distin-guishable, except in the thick barks of great old trees, and toward theinside next the wood ; the outer parts drying and breaking with innu-merable fifsures, growing wider and deeper, as the body of the treegrows bigger, and mouldering away on the outside.

Though it cannot appear, by reason of the continual decay of it, uponthe account aforesaid, yet it is probable the bark of a tree hath had suc-cefsively as many integuments as the wood; and that it doth grow by-acquisition of a new one yearly on the inside, as the wood doth on the■outside ; so that the chief way, and conveyance of nourishment to bothrhe wood and the bark, is between them both.

The least bud appearing on the body of a tree, doth, as it were, makeperforation through the several integuments to the middle, or very near;which part is, as it were, a root of the bough in the body of the tree*and after becomes a knot, more hard than the other wood : when grown

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