The grapes grown on the Pacific slope are almost exclusively Vinifera varieties, though a few American grapes are planted in the Pacific Northwest. This is not because American varieties cannot be grown, although they succeed rather less well here than on the eastern seaboard, but because the Viniferas are liked better, and climate and soil seem exactly to suit them. Viticulture on the Pacific slope is divided into three interdependent industries which are almost never quite independent of each other--the wine industry, raisin industry and table-grape industry. Each of these industries depends on grapes more or less specially adapted to the product, the special characteristics being secured chiefly through somewhat distinct types of grapes but depending partly on soil and climatic conditions. The manufacture of unfermented grape-juice is not yet a success in this region for the reasons that Vinifera grapes do not make a good unfermented juice, and American grapes are not grown in sufficient quantities to warrant the establishment of grape-juice plants. Bioletti gives the extent of the grape-growing industry in California as follows:[1] "The vineyards of California covered in 1912 about 385,000 acres. Of this total, about 180,000 acres were producing wine-grapes. Roughly, 50 per cent of the wine was produced in the great interior valleys, including most of the sweet wines; 35 per cent was produced by the valleys and hillsides of the Coast ranges, including most of the dry wines; the remaining 15 per cent was produced in Southern California and included both sweet and dry. "The raisin-grape vineyards covered about 130,000 acres, of which about 90 per cent were in the San Joaquin Valley, 7 per cent in the Sacramento, and 3 per cent in Southern California. "The shipping-grape vineyards are reckoned at 75,000 acres, distributed about as follows: 50 per cent in the Sacramento Valley, 40 per cent in San Joaquin, 6 per cent in Southern California, and 4 per cent in the Coast ranges." _The Chautauqua grape-belt._ The Chautauqua grape-belt, lying along the northeastern shore of Lake Erie in New York, Pennsylvania and Ohio, is the second most important grape region in America. The "belt" is a narrow strip of lowland averaging about three miles in width, lying between Lake Erie and a high escarpment which bounds the belt on the south throughout its entire length of a hundred or more miles. Here climate and soil seem to be exceptionally favorable for grape-growing. Climate is the chief determinant of the boundaries of this belt, since there are several types of soil upon which grapes do equally well in the region, and when the climate changes at the two extremities of the belt where the escarpment becomes low, or when the distance between the lake and the escarpment is great, grape-growing ceases to be profitable.