[137] An old Japan hand once counselled me that "the thing to find out in sociological enquiries is not people's religions but their superstitions." [138] See Appendix IV. CHAPTER XVII THE BIRTH, BRIDAL AND DEATH OF THE SILK-WORM (NAGANO) The mulberry leaf knoweth not that it shall be silk.--_Arab proverb_ One acre in every dozen in Japan produces mulberry leaves for feeding the silk-worms which two million farming families--more than a third of the farming families of the country--painstakingly rear. But the mulberry is not the only mark of a sericultural district. Its mark may be seen in the tall chimneys of the factories and in the structure of the farmers' houses. Breeders of silk-worms are often well enough off to have tiled instead of thatched roofs; they have frequently two storeys to their dwellings; and they have almost always a roof ventilator so that the vitiated air from the _hibachi_-heated silk-worm chambers may be carried off. Yet another sign of sericulture being a part of the agricultural activities of a district is its prosperity. Silk-worms produce the most valuable of all Japanese exports. Japan sends abroad more raw silk than any other country.[139] It is in the middle of the country that sericulture chiefly nourishes. The smallest output of raw silk is from the most northerly prefecture and from the prefecture in the extreme south-west of the mainland. But human aptitude plays its part as well as climate. The Japanese hand is a wonderful piece of mechanism--look at the hands of the next Japanese you meet--and in sericulture its delicate touch is used to the utmost advantage. The gains of sericulture are not made without corresponding sacrifices. Silk-worm raising is infinitely laborious. The constant picking of leaves, the bringing of them home and the chopping and supplying of these leaves to the smallest of all live stock and the maintenance of a proper temperature in the rearing-chamber day and night mean unending work. The silk-worms may not be fed less than four or five times in the day; in their early life they are fed seven or eight times. This is the feeding system for spring caterpillars. Summer and autumn breeds must have two or three more meals. The men and women who attend to them, particularly the women, are worn out by the end of the season. "The women have only three hours' rest in the twenty-four hours," I remember someone saying. "They never loose their _obi_."