PHYSICAL STRUCTURE OF VEGETABLE FIBRES QI 



presence of a very thick median layer of lignin between the 

 individual cells. The lumen of the cross section is also 

 usually rather thick, and often contains yellowish matter, 

 differing in these respects from hemp, in which the lumen is 

 flat, narrow, and always empty. 



The microscopical characteristic of the New Zealand flax 

 or hemp fibres is their remarkably slight adherence. The 

 fibre elements average about J in. in length, which is about 

 fifty-five times greater than their breadth. They are very 

 regular and uniformly thickened, and the surface is smooth, 

 exhibiting no markings or joints. The lumen is very apparent, 

 and is generally narrower than the cell wall, and is very 

 uniform in its width. The ends are sharply pointed, and not 

 divided. The cross section shows rather loosely adhering 

 elements, and is very round in contour, the lumen being either 

 round or oval, and is empty. The purified fibre of New 

 Zealand hemp is rather difficult to distinguish microscopically 

 from aloe hemp or from Sanseviera fibre, except by the 

 rounded and separated cross sections. 



Manilla hemp, as seen under the microscope, shows fibre 

 elements about ^ in. in length, and 3-^3 in. in diameter. The 

 bundles of fibres are very large, but by treatment with an 

 alkaline bath are easily separated into smooth, even fibres. 

 The fibres, which are very uniform in diameter, are lustrous 

 and rather thin walled. The lumen is large and distinct, but 

 otherwise the fibre does not exhibit any markings. The cross 

 sections are irregularly round or oval in shape, and the lumen 

 in the section is open and quite large, and distinct. The fibre 

 bundles often show a series of peculiar, thick, strongly silici- 

 fied plates, known as stegmata. Lengthwise these appear 

 quadrilateral and solid, and have serrated edges and a round, 

 bright spot in the centre. The lumen often contains a 

 yellowish substance, but no distinct median layer is perceptible 

 between the fibres. 



In their microscopical appearance the fibre bundles of 



