Compound Celluloses 109 



groups are sharply separated from one another. As the 

 student becomes more familiar with the subject, he will find 

 the constituent groups ' overlapping ' in an unmistakable 

 manner, with suggestions of probable genetic connections. 



Keeping, however, for the present, to the strictly empirical 

 view, we proceed to the systematic account of the jute fibre as 

 the typical lignocellulose. 



The JUTE FIBRE is the isolated bast of plants of the species 

 Corchorus (Order Tiliaceae), an annual of rapid growth, usually 

 attaining a height of 10-12 ft. in the few months required, 

 in the Indian climate, for the maturing of the plant. This 

 great length of stem is attained without branching, and the 

 separation of the bast from the wood and cortex is a manual 

 operation of the simplest kind. The plants, after being cut 

 down, are steeped or retted for a short period in stagnant 

 water ; the stems are then handled individually ; the wood 

 being broken, the bast is easily stripped and freed by washing 

 from the softened cellular cortex. The fibre is supplied to 

 commerce in long lengths, or strands, representing nearly the 

 full length of the parent stem. As, however, the lower portion, 

 6-8 ins. from the root upwards, is more or less reticulated, this 

 is usually cut off, and these rejections constitute the jute 'butts' 

 or 'cuttings' largely used as the raw material for special 

 classes of wrapping papers. The textile fibre is of a brown to 

 silver-grey colour in the finer sorts. The individual fibres, or 

 spinning elements (filaments), are complex structures ; in cross 

 section they are seen to be bundles of the ultimate fibres, the 

 number of which varies from 7 to 20. The ultimate fibre itself is 

 of short length, 2-3 mm. ; it is of circular or polygonal section, 

 with a central canal sometimes nearly obliterated, from the 

 thickening of the cell wall. These bast fibres taper off at their 

 extremities, and are built up by apposition to form the complex 

 filament or bundle. 



