account of temperature, summer is longer in the north, and localities in the Valley have more hours of heat than do those of south California. Hence that climatic characteristic of the entire Pacific Coast—already referred to and which is of extreme importance in determining the life-zones of California—the great amount of total annual heat supply at comparatively high latitudes. A low summer temperature enables northern species to push far southward, while the high heat total of the year enables southern species to push far north. The resultant intermingling of forms is very marked and characteristic of the Pacific Coast states. The distribution of life-zones is primarily a matter of altitude and corresponds to that of the isotherms. The mountain goat and mountain sheep live in the Sierran upper-land, though long ago well-nigh exterminated. The Douglas red squirrel is ubiquitous in the Sierran forests and their most conspicuous inhabitant. White-tailed deer and especially black-tails are found on the high Sierra; the mule deer, too, although its habitat is now mainly east of the range, on the plateau, is also met with. Grizzly, black, cinnamon and brown bears are all Californian species once common and to-day rare. When Americans began to rule in California elk and antelope herded in great numbers in the Great Valley; the former may to-day sometimes be seen, possibly, in the northern forests, and the latter occasionally cross into the state from Nevada. The sage-hen is abundant on the eastern flank of the Sierra. Grouse, quail, crows and woodpeckers (Melanerpes formicivorus) furnish species characteristic of the state. There are various species of ground-squirrels and gophers, which are very abundant. Noteworthy in the animal life of the lower Sonoran and tropic region are a variety of snakes and lizards, desert rats and mice; and, among birds, the cactus wren, desert thrasher, desert sparrow, Texas night-hawk, mocking-bird and ground cuckoo or road runner (Geococcyx Californianus). The California vulture, the largest flying bird in North America and fully as large as the Andean condor, is not limited to California but is fairly common there. In the zoology and botany of California as of the rest of the Pacific Coast, the distinctions between the upper austral and humid transition zones are largely obliterated; and as one passes southward into the arid lands, life forms of both these zones intermingle with those of the arid transition.
Fish are abundant. The United States fish commission, and an active state commission established in 1869, have done much to preserve and increase this source of food. In 1904 the yield of the fisheries of the three Pacific Coast states was 168,600,000 lbs, valued at $6,681,000,—nearly half that of the New England states, more than one-third that of the Middle Atlantic states and more than that of the South Atlantic and Gulf states combined. Of the total, California yielded between a quarter and a third. A third of her fish comes from the Sacramento river. Some 230—more or less—marine food fishes are to be found in the market at San Francisco. The exports of fish from that port from 1892-1899 were valued at from $2,000,000 to $2,500,000 annually. Native oysters are small and of peculiar flavour; eastern varieties also are fattened, but not bred in California waters. Shrimp are abundant; the shrimp fishers are Chinese and four-fifths of the catch is exported to China. Sturgeon were once the cheapest fish after salmon; to-day, despite all efforts to increase the supply, they are the dearest. Salmon, once threatened with extinction, have been saved, maintained in good supply, and indeed have probably regained their pristine abundance. Shad and striped bass are both very abundant and cheap. Black bass, flounders, terrapin, sea-turtles, perch, turbot, sole and catfish are also common. Great herds of seals once lay like toll-gatherers off the Golden Gate and other bays of the coast, taking a large share of the salmon and other fish; but they are no longer common. The sea-lions sometimes raid the rivers for 100 m. inland. They have greatly increased since hunting them for their hides and oil ceased to be profitable, and thousands sometimes gather on the Farallones, off the Golden Gate.
Flora.—Inclusiveness of range in the distribution of vegetable life is perhaps more suggestive than the distribution of animal species. The variation is from dwarf mountain pine to giant cactus and dates. The humid transition belt is the habitat of California’s magnificent forests. Nut pine, juniper and true sage-brush (Artemisia tridentata) characterize the upper Sonoran,—although the latter grows equally in the transition zone. Cereals, orchard fruits and alfalfa are of primary importance in the upper and of secondary importance in the lower Sonoran. In the arid portions of this and the tropic areas the indigenous plants are creosote, mesquite and alfileria bushes, desert acacias, paloverdes, alkali-heath, salt grass, agaves, yuccas (especially the Spanish-bayonet and Joshua tree) and cactuses. Among exotics the Australian saltbush spreads successfully over the worst alkali land. The introduction of other exotics into these zones,—made humid by irrigation, which converts them, the one into true austro-riparian the other into true humid tropical,—has revolutionized the agricultural, and indeed the whole, economy of California. At the two ends of Cajon Pass, only four or five kilometres apart, are the two utterly distinct floras of the Mohave desert and the San Bernardino valley. Despite the presence of the pass, plants do not spread, so great is the difference of climatic conditions. On the desert the same plant will vary in different years from 4 in. to 10 ft. in height when equally mature, according to the rainfall and other conditions of growth. Many mature plants are not taller than 0.4 to 0.8 in. The tree yucca often attains a height of 20 to 25 ft., and a diameter of 1.5 ft. About 600 species of plants were catalogued in desert California in 1891 by a government botanical party. The flora of the coast islands of California is very interesting. On Santa Cruz Professor Joseph Le Conte found 248 species, nearly all of which are distinctively Californian, 48 being peculiar to the surrounding islands and 28 peculiar to Southern California. Various other things indicate a separation of the islands from the mainland in quaternary times; since which, owing to the later southward movement on the continent of northern forms in glacial times, there has been a struggle for existence on the mainland from which the islands have largely escaped.
Forests.—The forests and agricultural crops of the state demand particular notice. In 1900 the woodland was estimated by the United States census at 22% of the state’s area, and the total stand at 200,000 million ft. of timber. The variety of forest trees is not great, but some of the California trees are unique, and the forests of the state are, with those of Oregon and Washington, perhaps the most magnificent of the world. At least the coniferous forests which make up nine-tenths of California’s woodland surpass all others known in number of species and in the size and beauty of the trees. Forty-six species occur, namely, 32 species of pitch trees (18 pines), 12 species of the cypresses and their allies (2 sequoia), and 2 species of yews or their allies. Peculiar to California are the two species of sequoia (q.v.),—the redwood (S. sempervirens), and the big-tree (S. gigantea), remnants of an earlier age when they were common in other parts of the world. The redwood grows only in a narrow strip on the Coast Range from Southern Oregon (where there are not more than 1000 acres) down nearly to the Golden Gate, in a habitat of heavy rains and heavy fogs. They cover an area of about 2000 sq. m. almost unmixed with other species. One fine grove stands S. of San Francisco near Santa Cruz. These noble trees attain very often a height of more than 300 ft., frequently of 350 and even more, and a butt diameter of more than 15 to 20 ft., with clean, straight fluted trunks rising 200 ft. below the lowest branches. They grow in a very dense timber stand; single acres have yielded 1,500,000 ft. B.M. of lumber, and single trees have cut as high as 100,000 ft. The total stand in 1900 was estimated by the United States census as 75,000,000,000 ft., and the ordinary stand per acre varies from 25,000 to 150,000 ft., averaging probably 60,000 ft. The redwood is being rapidly used for lumber. There is nowhere any considerable young growth from seed, although this mode of reproduction is not (as often stated) unknown; the tree will reproduce itself more than once from the stump (hence its name). In thirty years a tree has been known to grow to a height of 80 ft. and a diameter of 16 in. The wood contains no pitch and much water, and in a green condition will not burn. To this fact