The same operation is sometimes repeated for doors; but in recent years the mountain region where this pine grows has been supplied with factories and there is now less shipping of raw material out and of finished products back than formerly. The development of the fruit industry in the elevated valleys of Idaho, Montana, Washington, and Oregon has called for shipping boxes in large numbers, and western white pine has been found an ideal wood for that use. It is light in weight and in color, strong enough to satisfy all ordinary requirements, and cheap enough to bring it within reach of orchardists. It meets with lively competition from a number of other woods which grow abundantly in the region, but it holds its ground and takes its share of the business. Estimates of the total stand of western white pine among its native mountains have not been published, but the quantity is known to be large. It is a difficult species to estimate because it is scattered widely, large, pure stands being scarce. Some large mills make a specialty of sawing this species. The annual output is believed to reach 150,000,000 feet, most of which is in Idaho and Montana. MEXICAN WHITE PINE (_Pinus strobiformis_) is not sufficiently abundant to be of much importance in the United States. The best of it is south of the international boundary in Mexico, but the species extends into New Mexico and Arizona where it is most abundant at altitudes of from 6,000 to 8,000 feet. The growth is generally scattering, and the trunks are often deformed through fire injury, and are inclined to be limby and of poor form. The best trees are from eighty to one hundred feet high, and two in diameter; but many are scarcely half that size. The lumbermen of the region, who cut Mexican white pine, are inclined to place low value on it, not because the wood is of poor quality, but because it is scarce. It is generally sent to market with western yellow pine. Excellent grades and quality of this wood are shipped into the United States from Mexico, but not in large amounts. An occasional carload reaches door and sash factories in Texas, and woodworkers as far east as Michigan are acquainted with it, through trials and experiments which they have made. It is highly recommended by those who have tried it. Some consider it as soft, as easy to work, and as free from warping and checking as the eastern white pine. In Arizona and New Mexico the tree is known as ayacahuite pine, white pine, and Arizona white pine. The wood is moderately light, fairly strong, rather stiff, of slow growth, and the bands of summerwood are comparatively broad. The resin passages are few and large. The wood is light red, the sapwood whiter. The leaves occur in clusters of five, are three or four inches long, and fall during the third and fourth years. The seeds are large and have small wings which cannot carry them far from the parent tree.