Far more remarkable than the dwelling-houses or granaries of the Formosan aborigines are the long suspension-bridges, which with marvellous skill they construct of bamboo, held together only with deer-hide thongs, or occasionally with tendrils of a curiously tough vine growing in the mountains, and throw across the deep chasms and ravines which abound in the interior of the island, especially in the mountainous section inhabited by the Taiyal, Bunun, and Paiwan tribes. These bridges are now imitated by the Japanese, as regards shape and construction. Only the material is different, galvanized iron and wire being substituted for bamboo and thongs. Ingenious bamboo fences are also constructed by the Taiyal, surrounding their village communities. The weapons of the men, bow and arrows and knives, have been referred to before. Both knives and arrow-heads were formerly made of flint, but for many years iron has been used[90]; this being obtained by barter, until recently from the Chinese and now usually from the Japanese. The few old stone knives still remaining among them are regarded as sacred, and are used by the priestesses in warding off evil _Ottofu_ at marriage ceremonies and on occasions of illness--as has been described in preceding chapters. The knives are not of the wavy “kris” variety used by some of the Malay peoples, but have one curve, the cutting edge being on the convex side of this curve. The scabbard of this knife consists of a single piece of wood hollowed out to fit the blade. Across the hollowed-out portion are fastened twisted thongs of deer-skin or strips of bamboo, or--when these can be obtained--strips of tin, which hold the knife in place when it is sheathed. Old tomato-cans and milk-tins are now eagerly sought for this purpose, and much in the way of game and millet will be offered for them. The scabbard of a chieftain or of an honoured and successful warrior is decorated with coloured pebbles set into the wood; or, in the case of the Ami, who live near the sea-shore, with bits of shell or of mother-of-pearl. The handle of the knife is bound around with wire, when this can be obtained. Wire is considered highly ornamental, and is greatly prized, and eagerly bargained for. It is used for ornamenting pipes as well as knives, and is also bound about the arms, and worn as bracelets by both women and men; besides being worn as ear-rings by the men--twisted into huge rings, and thrust through holes in the lobes of the ears.