Although the best sheep for mutton were first developed in England and the best for wool,—the Merino—in Spain, the greatest commercial sources of both meat and wool arc new countries such as Australia and South America. Europe, to be sure, still has more sheep than any other continent and their quality is probably the highest, but for the most part their products are used locally. It must be remembered that quantity and quality by no means necessarily go together. The quantity of mutton and wool available for the market depends largely on the amount of land fit for sheep grazing and not needed for other purposes. Australia and Argentina are great sheep countries not because they are peculiarly adapted to the sheep industry, but because being fairly well adapted, they have vast available areas. The com mon history of new countries that arc covered with grass is that the early settlers often try to raise both sheep and cattle. But the sheep, being mountain animals adapted to eating grass which cannot grow long because of the low temperature, bite off the grass very short and often pull up the roots. Thus they clean off the ground so com pletely that the cattle have hard work to obtain a living. Accord ingly there is usually a bitter quarrel between sheep men and cattle men, a. quarrel which in the past in the western United States sometimes led to shooting. Since cattle usually pay better than sheep on good land, most of the sheep are ultimately forced into the mountains or into the drier regions less favorable for cattle. Thus in Australia the sheep industry is very prominent because a vast amount of land is not yet used for either cattle or agriculture, and much of it never can be. The sheep is the animal of the poor lands left over when more productive animals and plants have occupied as much as they profitably can, and such lands are likely to be rugged.
Why Trees are Mainly a Product of Regions of Rugged Relief.— Although lumber is one of the world's most important products, the areas of production arc being steadily reduced. The growth of trees is so slow that on good land the production of wood per year is rarely worth as much as the product of the same area when used for crops or even cattle. Moreover people do not like to wait fifty or a hundred years to harvest a crop. Hence, trees for the production of lumber are gradually being restricted to lands where cultivation is difficult or unprofitable. The difficulty may be due to climate as in the cold plains of Siberia, and the hot plains of the Amazon. It may be due to a combination of soil, swamps and other factors which prevent certain lands from being used for crops, as in the Gulf States. Where lowlands arc favorable in climate and soil, the chief reason why land is left in forests is ruggedness. In this respect trees are like sheep. In fact, sheep and lumber are two of the main products which rugged regions are likely still to produce after all the available land of gentle relief has been otherwise used, but sheep flourish in the drier regions, and timber trees in the moister areas. Hence, to-day the rougher parts of New England, New York, Michigan, Wisconsin, and 1\ linnesota, the southern Appalachian region, the higher parts of the Rockies and of the ranges farther west, and especially the western slope of the ranges near the Pacific Ocean in northern California, Oregon, and Washington are among the main lumber regions of the United States. Nevertheless, it must not
be overlooked that much lumber is produced in certain lowlands which have not yet been utilized for farms; Louisiana and Mississippi are thus among the chief lumber states.
The presence of mountains is often a help in producing the optimum climate for trees, for the mountains tend to cause rain not only on their windward slopes but often on the adjacent portion of lowlands. We judge of the opti mum from the size and vigor of the trees. Much the finest conifers grow in the bottom lands of the wet Pacific slopes of the western mountains of the United States. There grows the Oregon pine, or Douglas fir as it really is, which to-day rivals the southern pine as a wood available in large quantities for general purposes; there also grow the Washington spruce, the best kind of wood for airplanes where lightness, strength, and freedom from knots must be combined; the great redwoods of the California coast; and the giant sequoias, 300 feet high and 20 or even 30 feet in diameter at the base, and often 2000 or even 3000 years old. The southern slopes of the Himalayas at alti tudes of 5000 feet or more favor a similar, but less wonderful development of conifers, while the giant cedars of Lebanon, which are now almost extinct, on the western slope of the Lebanon range in Syria, seem to have been most vigorous when that region also enjoyed a climate similar to that of the coast ranges of our Pacific states. The essential features of that climate are first, such an abundance of snow in winter that the ground cannot freeze deeply and that the trees cannot suffer from the dryness which is especially injurious to conifers when all the moisture in the soil is frozen. A second essential is enough precipitation during the cooler months and a lo v enough temperature in summer so that in spite of a summer season with little rain, the ground does not become dry. Where the finest conifers grow, the summer months rarely have an average temperature above 60°, while the winter months are either fairly mild or have so heavy a snowfall that the soil does not freeze deeply. Such, conditions prevail primarily on the western slopes of mountains between latitudes 30° and 15°, but may prevail elsewhere. They are common chiefly on mountains because only where the land rises steeply not far from the sea is there likely to be enough rain and a sufficiently mild temperature. Not all mountains with windward slopes facing a great ocean, however, produce fine forests. In Alaska, although the forests on the Pacific slope are very dense, the low tem perature causes the trees to be small and poor like those of Siberia, except in the southern part close to sea level where a fairly high summer tem perature permits fine trees to grow.