The bast from the black walnut (_Juglans nigra_, L.) was encountered twice in burden straps from the Iroquois (Museum of the American Indian, Heye Foundation). These fibers had apparently been previously treated, both chemically and mechanically. They were probably boiled in ashes, pounded, and then straightened so as to make them usable in twisting cord and thread. One such specimen in the above Museum carries the catalogue number 16-5208. LINACEAE, Dumort. (Flax Family) Common flax (_Linum usitatissimum_, L.) is another example of introduced fibers used by the Indians in post-Columbian times. The fiber was probably secured in trade. It was found in five specimens made by the Winnebago, Potawatomi, Michigan, Ottawa, and Delaware Indians. In the Milwaukee Public Museum is a bag (14619), made by the Winnebago and composed entirely of flax cords. In a Delaware burden strap (50-7191) in this Museum the fine cords are linen, but the coarse cords are milkweed, _Asclepias syriaca_. In the Archaeological Museum of McGill University is a wampum belt (M5932), the beads of which are strung on a commercial linen thread. MALVACEAE, Neck. (Mallow Family) As was to be expected, cotton (_Gossypium herbaceum_, L.) became the most commonly and universally used of any of the fibers after it was introduced east of the Mississippi River. No specimen was encountered in the prehistoric material, but after its introduction and sale by traders it was the most commonly used fiber. It does not seem advisable to discuss these uses in detail, suffice it to say that it served all purposes for which string and thread are utilized. SALICACEAE, Lindl. (Willow Family) Black willow (_Salix nigra_, Marsh.). This species of black willow was used by the Menomini, Winnebago, Michigan Ottawa, and Ojibway Indians in the manufacture of bags, pouches, fish nets, and cord. A Menomini bag (MAIHF 8-1136) and a similar Winnebago bag (AMNH 50.1-903) contain black willow fiber. A Micmac fish spear (AMNH 50-4754) is wrapped with black willow twine. In the preparation of black willow fiber the bark was obviously stripped from the tree. Then the inner white bast tissue was removed and boiled in wood ashes; finally, this bast was pounded and rubbed to remove all the cementitious materials and loosen the fibers so they could be arranged more or less parallel to each other for twisting or spinning. In none of the specimens examined were crude strips of the inner bark used without preliminary treatment. TILIACEAE, Juss. (Basswood Family)