The productions of the Main island are, as might be expected, far more various. In the southern part, especially that part bordering on the Inland sea, the productions are to a large extent similar to those in the southern islands. Rice and cotton are raised in great abundance. Tea flourishes particularly in the provinces near Kyōto and also in the rich valleys of the east coast. Silk-raising is a principal occupation. Nearly one half in value of all the exports from Japan is raw and manufactured silk, and a large part of the remainder is tea. The principal food raised in nearly all the islands is rice. The streams of water which abound everywhere make the irrigation which rice cultivation requires easy and effective. Besides the rice which is raised in paddy land there is also a variety called upland rice. This grows without irrigation but is inferior to the principal variety in productiveness. In the early rituals of the Shintō temples prayers were always offered for the five cereals. These were understood to be rice, millet, barley, beans, and sorghum. All these have been cultivated from early times, and can be successfully raised in almost all parts of the islands. Rice cannot, however, be raised north of the Main island. Millet, barley, and beans are cultivated everywhere, and are the principal articles of food among the country population. Buckwheat is also cultivated in all northern parts. It is believed to have been introduced from Manchuria where it is found growing wild. The domestic animals of Japan are by no means so abundant as in the corresponding parts of the continent. The horse has existed here from antiquity but was only used for riding or as a pack-horse, but never until recently was used for driving. The cow, owing perhaps to the restrictive influence of the Buddhist doctrines, was never used for food. Even milk, butter, and cheese, which from time immemorial formed such important articles of food throughout Europe and among the nomadic peoples of Asia, were never used. Sheep are almost unknown even to this day, and where they have been introduced it is only in very recent times and by foreign enterprise. Goats are sometimes but not commonly found. On the island of Ōshima,(12) off the province of Izu, they had multiplied to so great an extent and were so destructive to vegetation that about 1850 the inhabitants combined to extirpate them. Swine are found in the Ryūkyū islands, where they had been brought from China and they are found only incidentally in other places when introduced by foreigners. Dogs and cats and barnyard fowl are found in all the islands.