It would be well nigh impossible to enumerate all the species which are now known in the Cotton plant family, and it is not proposed here to describe more than the principal types of the Gossypium. In a report prepared by Mr. Tracy of Mississippi, U. S. A., no less than one hundred and thirty varieties of American cotton are given. He says: "The word 'variety' refers exclusively to the various forms and kinds which are called varieties by cotton planters, and is not restricted to the more marked and permanent types which are recognised by botanists. Of botanical varieties there are but few, while of agricultural varieties there are an almost infinite number, and the names under which the agricultural varieties are known are many times greater than the recognisable forms." The Cotton plant most readily responds to any changes of climate, methods of cultivation, change of soil or of fertilizers. So that it is easy to understand in a plant so susceptible and prone to vary as is the cotton, that new species may in a few years be brought into existence, and especially by means of proper selection of the seed, and careful cultivation.
The chief commercial types of Gossypium are—1. Barbadense; 2. Herbaceum; 3. Hirsutum; 4. Arboreum; 5. Neglectum; 6. Peruvianum.
Gossypium Barbadense.—The fine long silky fibres of commerce are all derived from this species. It is indigenous to a group of the West Indian Islands named the Lesser Antilles. It gets its name from Barbadoes, one of the West Indies. At the present time it is cultivated throughout the Southern States of North America which border on the sea, in most of the West Indian Islands, Central America, Western Africa lying between the tropics, Bourbon, Egypt, Australia, and the East Indies. There is no doubt that the plant comes to its highest and most perfect state of cultivation when it is planted near the sea. Dr. Evans says: "It may be cultivated in any region adapted to the olive and near the sea, the principal requisite being a hot and humid atmosphere, but the results of acclimatisation indicate that the humid atmosphere is not entirely necessary if irrigation be employed, as this species is undoubtedly grown extensively in Egypt." The height of this species varies from 3 to 4 feet if cultivated as an annual, and from 6 to 8 feet if allowed to grow as a perennial. When in full leaf and flower, it is a most graceful-looking plant. Yarns having the finest counts, as they are called, are all spun from Sea Islands, which belongs to this class. When we are told that a single pound of this cotton is often spun into a thread about 160 miles long we can see that it must be exceedingly good and strong cotton to do this.
Fig. 4.—The Gossypium Barbadense.
Lint is the name given to the cotton which remains when separated from the seeds. Every other American type of cotton gives a greater percentage of lint than the Sea Islands cotton, though it should be stated that the price per pound is greater than any other kind of cotton grown in the States. There are from six to nine seeds in each capsule and the prevailing colour is black. A cotton grown in Egypt and known by the name Gallini is of the Sea Islands type and has been produced from seed of the G. Barbadense. It should be added that the colour of the flower is yellow and that in India this plant is known by the name of Bourbon Cotton.
Gossypium Herbaceum.—As indicated by the name, this type is herbaceous in character, especially the cultivated type. When Lamarck classified this tree, he gave it the name Indicum because he considered most of the Indian types and some of the Chinese belonged to this particular species. India, too, is considered by Parlatore to have been the original home of the herbaceous type, and he specially fixes the Coromandel Coast as the first centre from which it sprang. There is much conflict of opinion in localising the primitive habitat of this type, and it is now thought that the present stock is probably the result of hybridisation of several species more or less related to each other. However, the areas in which this class of cotton grows are very numerous and extensive, for we find it growing in India, China, Arabia, Persia, Asia Minor, and Africa. A very characteristic feature of this plant is that it quickly decays after podding, when cultivated as an annual.
The Vine Cotton grown in Cuba belongs to the herbaceous type and is remarkable for its large pods, which contain an abnormal number of seeds. The so-called "Nankeen" cottons are said to be "Colour variations" of the herbaceous Cotton plant. Many varieties of Egyptian cottons are produced from this particular class, as well as the Surat cotton of India.