That originally nearest the centre of the tree is more open textured and almost invariably lighter in color than that near the outer portion of the ring.
The inner portion was formed early in the season, when growth was comparatively rapid and is known as _early wood_ (also spring wood); the outer portion is the _late wood_, being produced in the summer or early fall.

In soft pines there is not much contrast in the different parts of the ring, and as a result the wood is very uniform in texture and is easy to work.
In hard pine, on the other hand, the late wood is very dense and is deep-colored, presenting a very decided contrast to the soft, straw-colored early wood.

(See Fig.

23.) In ring-porous woods each season's growth is always well defined, because the large pores of the spring abut on the denser tissue of the fall before.

In the diffuse-porous, the demarcation between rings is not always so clear and in not a few cases is almost, if not entirely, invisible to the unaided eye.