After exhausting the list of plants that may be termed commercial fiber substitutes, in different countries where they grow, there still remains a much larger list of species that are chiefly interesting in a scientific enumeration of those plants which produce in their stalks, leaves, or seed vessels what may be termed fibrous substance. My own catalogue of the fibers of the world already foots up over one thousand species of plants, and the complete catalogue for all countries might extend the list to a thousand more. In considering the undeveloped fibers of the United States, it will be seen we should only recognize the actual commercial forms which we do not produce, but which may be produced within our borders, or such native growths as may be economically employed as their substitutes, and which possibly might be brought into commercial importance. The hemp industry is already established, though it should be extended in order to recover its lost position among American rural industries. Where in the past we produced forty thousand tons of hemp in the United States, we now produce less than a fifth of this quantity. The cultivation of flax in the United States before the days of the present factory system was so widespread that it was of national importance. Its manufacture was largely a home industry, however, conducted by the fireside, and, as in ancient Greece and Rome, the work was performed by the women of the household. With the advent of the factory system came competition; the housewife laid aside her spinning wheel, the clumsy home-made loom fell into disuse, and the farmer grew no more flax for fiber. Then the flaxseed industry was extended, and after the close of the war a large demand sprang up for coarse fiber for the roughest of uses--for bagging and upholstery, in connection with hemp--and hundreds of little tow mills came into existence in the Middle and Western States. The introduction of jute opened another chapter, and the decline of this crude attempt at a flax industry is recorded. Meanwhile some line flax was produced, but the extension of spinning and weaving establishments made a larger demand for this fiber, which was chiefly imported. Land in the old flax-growing States became more valuable for other crops, especially with the low prices brought about by foreign competition, and gradually the flax culture in the United States became a thing of the past.