freezing and no snow except in the mountains, California is an ideal place for a man who wishes to keep busy in the open air during nearly all the year, and to secure maximum results from annual activity of men, animals and machinery. It is obviously beyond the scope of this writing to undertake presentation of detailed data of California climatology or to discuss its salubrity from the points of view of physical comfort or escape from invalidism. The reader may draw inferences for himself from the somewhat new arrangement of meteorological data (set forth in Appendix B) which draws records from end to end and from side to side of the State-collocating them to show variations due to longitude, elevation, distance from the ocean, and the like. The arrangement also emphasizes the characteristics of the several regional subdivisions of California indicated in Plate III. Considering the geographical area included and the long periods of time covered, the tabulation in Appendix B comprises a summary of volumes of meteorology and by citing extremes as well as means of temperature for each month of the year, indicates with great definiteness what may reasonably be expected at any season in any region which the records represent. The data thus set forth, in connection with the descriptions of phases of rural life and the different requirements of various plants included in crop production, which will be undertaken in later chapters, can readily be translated into terms of significance to other phases of human life and industry. REGIONAL AGRICULTURE OF CALIFORNIA Although general statements based on the climatic satisfaction of the orange will apply to vast areas of California, as indicated, there are some parts in which such generalization is less true and some other sections in which it does not apply at all. It is this departure of the local from the general which gave rise to the claim that California has not one but many climates: in fact, from slight variations in temperature, moisture and soil conditions, measured by the particular requirements of different plants, there may be several climates on a single farm of a few hundred acres. Of course, soil suitability, moisture, exposure and the like, must be more or less closely prescribed and provided everywhere. The problem, however, is more complex in California than in most other farming states because a diversified topography makes more elevations and exposures, each with its own special characters, available for choice; also because crops are widely grown by two great water systems, rainfall and irrigation: and because California undertakes practically all the crops which are grown in the United States and adds to these some for which all the remainder of the country claims no adaptation. Realization that similar producing conditions group themselves in all parts of the State, not by degrees of latitude but by similarity which runs largely along lines parallel to the coast line and to the trend of mountain ranges, can best be attained by tracing resemblance from the point of view of crop production through several subdivisions of the State as indicated on the accompanying regional map (Plate III). The descriptions of the divisions that follow will also include references to the meteorological factors of temperature, rainfall and the resort to irrigation when needed to meet the moisture requirements of different crops. 1 The following statement of agricultural subdivisions of California, prepared by the writer after four decades of local observation throughout the State, was first published by the California Experiment Station in 1914 and is presented herewith with revisions suggested by later experience. Grouping local climatic conditions in their relation to crop production, the State may be divided into five regions, in which there will be some climatic features common to all, though they severally manifest sufficient differences of climatic conditions to determine roughly particular agricultural adaptations in all of them, viz: 1. Northwest Coast region. 2. Central Coast region. 4. Interior Valley region. 5. Mountain and Plateau region. The Northwest Coast region. This section is hilly and mountainous, being covered principally by the Coast Range and its foot 1Appendix B is arranged to show typical differences at similar latitudes and striking similarities, according to topographical conditions, with great differences in latitude. hills. The valleys are relatively small and irregular, although the Eel River Valley has great area and the flat lands at Humboldt Bay are broad and rich. The important climatic features are the moderate temperatures throughout the year, the high annual rainfall, and the prevalence of high winds and fogs along the coast. In most parts the rainfall varies from 40 to 100 inches, the variation being mainly due to elevation. Rains begin earlier in the fall and continue later in the spring than in other divisions of the State, but the rainfall is always smallest in July and August. This region most nearly resembles the East North Central and Middle Atlantic states in its agricultural operations and possibilities. It is eminently suited for the production of forage grasses and clovers, though alfalfa is less grown because of cool summers. Grains chiefly raised are barley and oats; corn and sorghums are likely not to ripen for lack of heat. The chief industry is dairying with grazing and root-crops. Apples and berries succeed admirably. The Central Coast region. This region includes coast slopes, many small valleys, a few of considerable size, and a large area of foothills and mountains west of the high ridge of the Coast Range, which at several points attains an elevation of about 4000 feet. Among the valleys are those of the San Francisco Bay district, the pioneer regions of commercial crop-growing and which now constitute one of the largest highly developed and densely populated agricultural sections of the State. Central in this district lies the city and county of San Francisco, which enjoys the unique distinction of having produced the tallest sky-scrapers and the broadest cabbage fields in California. North of San Francisco the coast valleys are great producers of dairy and poultry products, fruits and field crops. South of San Francisco are the bay-shore valleys long noted for truck crops, fruits (the prunes of Santa Clara and the apples of Pajaro valleys) and the hay, grain and sugar-beets of Salinas and Santa Maria valleys, while adjacent hill lands are largely used for grazing and, on the coast side, for the dairy industry. The southern end of this region, comprising valleys and coast slopes, produces, in addition to grazing and dairying, sugar-beets and beans in abundance, and several situations are famous for their apples. The Central Coast region is very diversified in topography, intermediate in temperatures and rainfall between its neighboring coast districts north and south. It has a range of products wide as the State itself, except that citrus fruits are not commercially produced, although grown by amateurs at favoring elevations and exposures. The Southern Coast region. This region extends from the point where the coast takes a sharp eastward turn and proceeds southward to the southern boundary of the State. Its width |