14 COTTON 



cake, or residue remaining after the oil has been 

 expressed, is used extensively as a feeding stuff for 

 cattle. Ginned Upland cotton seed consists approxi- 

 mately of linters, 10 per cent. ; hulls, 35*8 per cent. ; 

 oil, 20 per cent. ; and oil-cake, 34*2 per cent. 



According to the length of the individual fibres, 

 cotton is classed commercially as long-, medium-, or 

 short-stapled. The long-stapled cottons are from 

 about i J to i inches or more in length, the medium- 

 stapled about to i inch, and the short-stapled from 

 f to | inch. 



The principal long-stapled varieties are Sea Island 

 cotton, the Egyptian varieties, and the so-called 

 " improved " American Upland cottons which have 

 been obtained from ordinary Upland types by con- 

 tinuous selection and careful cultivation. The 

 Brazilian and Peruvian cottons vary in length from 

 i to i J inches, and are therefore either medium- or 

 long-stapled. The chief medium-stapled cottons of 

 commerce are the ordinary American Upland kinds, 

 and the short-stapled class is represented by the East 

 Indian varieties. 



STRUCTURE AND COMPOSITION OF THE COTTON FIBRE 



The cotton fibre or hair is a single hollow cell 

 without any transverse partition. The hair is of 

 the form of a long, narrow tube or cylinder, the 

 base of which is attached to the seed-coat ; its 

 greatest diameter is at a point about one-third of its 

 length from the base. As the hair ripens, it loses its 

 cylindrical form and becomes more or less flattened, 

 and then appears as a narrow, somewhat opaque 

 ribbon or band with slightly thickened, rounded edges. 

 The surface of the hair is smooth and the fibre 

 would therefore be difficult to spin were it not for the 

 fact that it possesses a peculiar characteristic twist. 

 This twist is not present in the early stages, but only 

 becomes developed after the boll has opened and 

 the cotton has been exposed to air and sunlight. 

 The twists are not formed by complete revolutions 



