21. No definite relation exists between the annual rings of growth and the amount of sapwood . 22. The heartwood is moderately durable and the sapwood is liable to powder-post beetle attack. 23. The higher longitudinal permeability of sapwood of hardwood is generally caused by the presence of vessels. 24. The heartwood varies from yellowish pink through reddish brown while sapwood is generally lighter in color. 25. The sapwood is gray-yellow, whereas the heartwood is bright purple with dark stripes. 26. Wide rings are indicative of a fast-growing tree with more sapwood and not much heartwood. 27. Sapwood is concentrated along one edge of each board, and it can easily be cut off.28. As the tree gets larger, the sapwood must necessarily become thinner or increase materially in volume. 29. The sapwood is typically cream-coloured and the heartwood has various shades of brown and purple. 30. The colour ranges from creamy white in the sapwood to a dark chocolate colour in the heartwood.
