What is known as the Citrus Belt of California is a great valley lying between the Coast Range on the west and the Sierra Nevadas on the east, and runs in a direction northwest to southeast, and extends from Red Bluff on the north to the Tejon Mountains on the south. The total area is about 17,200 square miles. This great valley contains about one-half of all the fruit trees and a third of all the vines in the State. Within the limits of this belt to the northernmost boundaries, in favored spots the orange flourishes side by side with the apple. Immense tracts of this great valley are used for agricultural and pasturage purposes, and, as yet, orchards occupy but an insignificant area of this immense valley. Several characteristics of the California climate and soil conjoin not only to produce glorious flowers, both wild and cultivated, but the greatest possible variety of fruits and berries. The abundant heat, almost perennial sunshine, and dry atmosphere, together with the fine adaptability of the soil and the great length of the growing season, join forces to produce fruits of superior size and excellence. The trees are amazingly prolific bearers, and also produce mammoth fruit. All conscientious horticulturists resort to the "thinning out" process in order to preserve the quality and size of what they allow to remain on the trees. The fruit industry in California, in spite of the immense crops matured every year, is but in its infancy. Millions of trees and vines are not yet in bearing, or only yielding third, fourth, and fifth year crops. Since the formation of the Fruit Growers' Union in 1881, when the first law was enacted to protect California horticulturists, there has been steady progress and practical expenditure of brains and money to further the interests, in every way possible, of the fruit growers of California. Horticulture has been reduced to a science by disseminating knowledge and a hearty coöperation of fruit growers to extend the interests of the State in every way possible. The history of horticulture in the State of California almost up to the present time has been one of experimenting, ascertaining the adaptability of the soil to certain kinds of fruits, and testing what European and Eastern trees do well in this climate, for many varieties make utter failures, while others are improved beyond recognition. Californians have had to learn also that a horticultural precedent has been established here, independent of what obtains in other countries. Although ideas and methods have been gleaned from abroad, application to local and special needs have metamorphosed them to a great extent. Hap-hazard planting in California is humbug unless wedded to Yankee shrewdness. Know your soil and its elements, the atmosphere, heat, and moisture and exposure; then ascertain what fruits do well under those limitations.