488 ON TROPICAL FIBRES. 



All vegetable fibres used for textile purposes, resolve themselves into 

 three great classes, viz., Foliaceous fibres, Cortical fibres, and Capsular 

 fibres. 



1. Foliaceous fibres. — These are obtained from Endogenous or Monocoty- 

 edonous plants, or inside-growers, which are best known to us in their 

 herbaceous forms, such as the grasses, including the cereals, sugar-cane, 

 and common cane, as also the lily, the cat-briar, and all plants in 

 which the leaves have parallel veins. Under and near the tropics, the 

 endogens are represented by the yuccas, the agaves, the plantain, and 

 the great family ot palms. These plants do not form a regular bark, 

 show no signs of annual growth, and do not increase by continual addi- 

 tions to the outside of the stem, as is the case with the trees common to 

 our climate. Their fibres are imbedded in the cellular tissues and pulpy 

 matter of their stems and leaves, and may in most, if not all cases, be 

 extracted by a purely mechanical process. The fibres known as Manila 

 hemp, Sisal hemp, silk-grass, etc., are obtained from plants of this class. 

 It is only in tropical and sub-tropical regions that endogenous plants 

 attain any great development, take aborescent forms, or yield fibres 

 suitable for textile purposes. To an inhabitant of the northern tem- 

 perate zone, an endogenous plant of which the green leaves yield valua- 

 ble fibres, is a curiosity only to be seen in conservatories or botanical 

 gardens. 



2. Cortical fibres. — These are obtained from what are botanically 

 known as Exogenous or Dicotyledonous plants, or outside-growers, and are 

 contained in their bark or bast. They are often of great length, but 

 little hardened, and with the exception of cotton, are the most valuable 

 produced in temperate climates. Some of the plants of this class attain 

 great size. A familiar example is the linden Cbass or bastwood) of 

 Europe and America, and the wild-fig or banyan tree of the tropics. A 

 greater number, however, are herbaceous, such as most of the Mallows, 

 in which is embraced the cotton plant), a large part of the Urticu or 

 nettle family (embracing the familiar hemp), the Linacea or flax family, 

 and some varieties of the Leguminosce or pea and bean tribe, such as 

 the Crotalaria juucea, which supplies the Sunn or Bengal hemp. The 

 stems of these plants consist of a woody core, surrounded by a sheath of 

 fibrous texture, and the two ere connected by a peculiar vegetable 

 glue, which unites them in a solid stem. In the preparation of flax, 

 hemp, China-grass, etc., the object is to remove this matter, and thus 

 separate the useless stem from the valuable external sheath of fibres. 



3. Capsular fibres. — These, as the name indicates, are obtained from 

 pods or capsules. Cotton, a familiar type of this class, is found in the 

 capsules of the Gossypium, enveloping the seeds, and in nearly all cases 

 closely adhering to them. 



