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conifers, which have a much more restricted distribution. In Montana it is associated with the western larch: in California it encroaches on the redwood belt; in south- western Oregon it is mixed with the Lawson cypress; while in the rest of the great forest of this state, and of Washington and northern Idaho, Thuya plicata is usually its constant companion. The various silver firs, hemlocks, and the Sitka spruce also take part, in different localities, in the mixture of coniferous trees in the Douglas forest. Towards the edges of the prairie regions and in the drier parts of the mountains, the Douglas fir gradually gives place to Pinus ponderosa, which is the characteristic tree of dry soils, where a very moderate rainfall prevails.

The northern limit of the Douglas fir extends from near the head of the Skeena River, latitude 54°, in the coast range of British Columbia to Lake Tacla in the Rocky Mountains, latitude 55°, reaching its most easterly point near Calgary in Alberta. In the coast range, the tree grows at some distance inland north of latitude 51°; while south of this line it is common on the coast of the mainland and in the island of Vancouver ; and in this region, and in Washington and Oregon, between the western foothills of the Cascades and the sea, it is most abundant and of its largest size. It attains its maximum development, 300 feet in height, in Vancouver Island and on the northern slopes of the Olympic Mountains in Washington, where the rainfall is excessive ; whereas, on the Cascades and in the interior of the continent, it rarely exceeds 150 feet in height. It is common, but only of moderate size, in the forests of northern Idaho and of western Montana,’ ascending to 6000 feet.

The Douglas fir extends southwards along the Rocky Mountains, in the Yellowstone Park in Colorado, where it grows between 6000 and 11,000 feet altitude ; in Utah, to the east of the Wasatch range; in northern and central New Mexico and northern Arizona, where it is common between 8200 and 9000 feet, being rare and of small size in the southern parts of these two states, where it ascends to 6000 or 7000 feet; in the Guadalupe Mountains of western Texas, where it is abundant; and it spreads into Mexico, along the Sierra Madre range of Chihuahua and the mountains of Nuevo Leon, reaching its most southerly point near the city of San Luis Potosi.

In California it extends southward in the coast mountains’ as far as Punta Gorda in Monterey county, but is not abundant, and is rarely over 150 feet in height ; inland it extends to the Sierra Nevada,* where it grows to a large size and ascends to 7000 feet. It does not occur in the arid tracts of Nevada and Utah, which lie between the Sierra Nevada and the Wasatch ranges. (A.H.)

So little seems to be known by British foresters as to the conditions under which the tree grows in America, that though I quite agree with the preceding account, it may be as well to add some of my personal experience of the tree as I saw it on my last journey in 1904. In the Blackfoot valley of Montana it is associated

1 At Whitefish, Montana, an average tree, growing with the western larch, was 140 feet in height and 8 feet in girth, and showed 245 annual rings ; the sapwood, ¾ inch wide, containing 45 rings; the bark was 2½ inches in thickness.

2 Jepson, in Flora Western Mid. California, 19 (1901) says that it is frequent in the Santa Cruz mountains; but is not known in the Mt. Diabolo and Mt. Hamilton ranges, or in the Oakland hills.

3 Sargent in Garden and Forest, x, 25 (1897), says that it does not extend in the Sierras, south of the head of King’s river, or within 100 miles of the territory occupied by P. macrocarpa. Jepson (op. cit. 20), makes its southern limit on the Sierras, about the head-waters of Stevenson Creek, which is not far from the head of King’s river.