The flowers are white, or pale yellow, or cream-colored the first day. They darken and redden on the second day, and fall to the ground on the third or fourth day, leaving a tiny boll developed in the calyx. This boll develops and enlarges until maturity, when it is somewhat like a hen’s egg, both in size and shape. This boll is the house of the seed and lint--the products of commerce. In it are from three to five apartments or cells (often more than five in improved types), which hold the lint from its earliest formation until it is picked in the fall. The bolls of the cotton plant mature all the way from the last of August until frost attacks them. When matured, the fibrous wool, known as seed cotton, is gathered, ginned, and baled. When separated from the seed the lint becomes the cotton of commerce.
The chief commercial types of cotton are American upland, sea island, Egyptian, India, Brazilian and Peruvian. These differ in the length of the individual fibers (staple). The quality is indicated by the grading under such names as fine, good, good fair, fully fair, middling fair, good middling, middling, etc. Sea island cotton has the longest staple and is used for the finest qualities of yarn and fabrics. Egyptian cotton also has a long staple. Large amounts are imported into the United States.
Cotton is next to corn the most valuable farm crop of the United States. Nearly three-fourths of all the cotton produced annually in the world is grown in the south Atlantic and gulf states. The remainder comes mostly from India, Egypt, China, Brazil, and Asiatic Russia. A comparatively small percentage of the crop is sea island cotton from the coast of Georgia and from islands in the West Indies. The area of cotton production is spreading in the United States as well as in foreign countries.
Cotton fiber is spun into yarn and made into thread, muslin, calico and hundreds of other cotton or part cotton fabrics. Mercerized yarn is prepared by treatment with strong caustic alkali. Cotton linters are used in cheap yarns, cotton batting, mattresses, and the manufacture of celluloid and artificial silk.
Cotton seeds are subjected to heavy pressure in machines in order to extract the oil. The oil-cake is a valuable cattle food and the hulls are used for fuel or for paper making.