109 



to l>e white and transparent, like filaments of spun glass, and where it lies in 

 bundles it has a lustre like satin. 



When mounted in " Deane's gelatine," and examined by transmitted 

 light with a power of 225 linear, the ultimate fibres appear to be cylindrical 

 tubes of considerable length (probably one and a half to two inches, but I have 

 not succeeded in tracing any one cell through its whole length), the margins 

 extremely smooth and regular, the finest of the fibres quite as fine as the silk 

 of the Bombyx Mori, or mulberry silkworm. The cells taper gradually to each 

 end, and are slightly rounded at the point. A central canal of considerable 

 size is plainly visible. I observed no transverse or longitudinal markings on 

 the fibre. The central canal appeared to be filled with air only, when I 

 examined the fibre in August, but this may not be the case at all seasons of 

 the year. 



Transverse sections of the upper part of the leaf, mounted in " Deane's 

 gelatine," and examined by transmitted light with a power of 225 linear, 

 show that the fibres are not round, but roughly hexagonal, with slightly-rounded 

 angles packed closely together in bundles, but so that small interspaces are 

 left at the i^ounded angles. The central canal is marked by a - well-defined spot 

 on each ultimate fibre ; and around this spot are slight indications of concentric 

 lines, showing how the cell has been built up by successive deposits of 

 cellulose. 



The ultimate fibres vary considerably in diameter, those near the green or 

 upper-surface of the leaf being much finer than those near the dull under-surface 

 of the leaf. 



"When the ultimate fibres are broken, they break transversely, and the 

 fracture has a ragged edge. I could not discover any tendency to tear 

 longitudinally into finer filaments. 



The bundles of fibre are in the form of flattened bands, arranged with 

 tolerable regularity, parallel to each other, lengthwise in the leaf, one edge of 

 the band being close to the green or upper-surface of the leaf, the other edge 

 close to the dull or under-surface. Some of the bands appear to be incomplete, 

 and extend only to a short distance from the surfaces of the leaf. 



In the centre of each complete bundle of fibres is a brown bundle of spiral 

 or vascular tissue, the central canals in this tissue are larger than the central 

 canals in the fibre. This spiral tissue appears to break up very easily and to 

 separate readily from the woody tissue or fibre. 



The bundles of fibre are imbedded in the cellular tissue, known as the 

 parenchyma, or more accurately as the merenchyma, of the leaf, and are 

 immediately surrounded by a layer of cylindrical cells very similar to the cells 

 just beneath the cuticle of the leaf. 



The cells of the cellular tissue are, for the most part, filled with the 

 greenish fluid juices of the plant : the grains of chlorophyll — the waxy, green 

 colouring matter of the leaf — being very conspicuous in the cells near the 

 tipper surface. 



In the lower or butt ends of the leaf, the ultimate fibres are much coarser, 

 the bundles are cylindrical or oval, there is a great thickness of cellular tissue 

 in which the bundles of fibre are imbedded, and the cells surrounding each 

 bundle are filled with some reddish colouring matter, which, in some cases, 

 seems to pervade the whole cellular tissue. 



The fibre appears to be quite white and colourless in every part of the 

 leaf, until the cells in its neighbourhood are ruptured. 



From the above microscopic examination of the leaf and fibre, T have 

 come to the conclusion that an erroneous opinion is prevalent on the following 

 points, which are important : — 



1. There is no woody matter to be separated from the fibre ; the spiral 



