A similar transformation takes place under the influence of certain fatty seeds, e. g. those of rape and colza; and it is probable that the formation of cellulose in living plants may take place at the expense of saccharose and under the influence of ferments. In support of this it has been established that in the sugar-cane, the formation of wood—i.e. cellulose—is accompanied _pari passu_ by a decrease in saccharose. More recently, A. Brown (_Chem. Soc. Journ._, 432, 1886) has investigated the formation of cellulose by the “vinegar plant” growing in solutions of the carbo-hydrates, e. g. dextrose in yeast-water. The cells elaborate an extra-cellular fibrin, which acts as a “cell-collecting medium,” and they possess therefore a two-sided activity, i.e. the property above mentioned, in addition to their strictly fermentative activity. The cellulose film in question was found to contain 50 to 60 per cent. of pure cellulose. It is noteworthy that in a solution of levulose the growth of the “plant” is unattended by fermentative action, 33 per cent. of the substance being, on the other hand, transformed into cellulose. _Modifications of Cellulose in the Plant. Compound Celluloses._—It has been already stated that cellulose occurs in nature for the most part in a form different from that in which we have hitherto considered it, viz. either combined or mixed with other substances which are of such a nature that they may be removed by a chemical process, more or less simple. One of the most characteristic of these modified celluloses constitutes the jute fibre, the isolated bast of an Indian plant, {17} which has an enormous industrial application for the coarser textile purposes. The chemistry of jute throws light on the course of lignification, the process by which cellulose is modified into wood, and in studying it in preference to wood we have the advantage of studying a simple tissue. Like cellulose, jute dissolves in cuprammonia, and is similarly acted upon by the concentrated acids. By nitric acids it is converted into nitric ethers, which are yellow coloured, but in other respects closely resemble the pyroxylins. They are entirely soluble in acetone. Jute differs from cellulose in the following respects: its percentage composition (excluding ash) is C 47·0 48·0 per cent. H 5·9 5·7 „ O 47·1 46·3 „