arboreta* is given. It is a small tree and grows about the temples, but is not cultivated to any considerable extent. It produces a fine silky staple, but its former high value is now believed to have been overrated. This cotton usually called Nurma, from its growing about temples, is also known as Deo cotton. From South America are received a number of varieties of cotton that have usually been attributed to G. peruvianum. They have a short, strong, curly fibre somewhat resembling wool and their smooth black seeds adhere in an oval mass, on which account they are called kidney cottons.
i The plant which produces this cotton is a small short-lived tree and like the Nurma cotton of India will not mature in the United States.
When considered commercially the fibre pro duced by the seed is the most valuable product of the cotton plant. Viewed under a good mi croscope it appears to be an irregular, flattened, twisted tube, the edges of which are somewhat thickened and corrugated. This twist distin guishes cotton from all other fibres and it is to this character that its superior value for spin ning is due. The fibre of some of the wild species of cotton does not possess this twist and such as do not are of little value. If not thoroughly matured the fibre is more flattened, less twisted and thinner walled. Such fibres, if abundant in a sample, depreciate its value as they curl up, do not spin well nor dye evenly. Among the leading commercial types of cotton the fibre varies from one-half inch to two inches or more in length and is exceedingly fine, the extreme diameter measurements being 0.0084 to 0.0064 inch, the longest and finest fibre being of the Sea Island types. The commercial grad ing of cotton is as follows: Samples, the aver age fibre of which is under 0.98 inch (25 milli meters) in length are called °short staple; those between 0.98 and 1.17 inches (25 to 30 mil limeters) are called °medium° and from 1.18 to 1.57 inches (30 to 40 millimeters) are called "long staple.° Those exceeding 1.58 (40 milli meters) are "extra long.° The °lone and "extra long° fibre produced in the United States are all from Sea Island varieties and their hybrids, the shorter ones being usually Upland cottons of the G. herbaceum type. Other classi fications adopted by the New York Cotton Ex change are: What are known as °full are dtsignated by the words °middling fair,"good middling,) "middling,° "low mid °good ordinary° and °ordinary.° To designate qualities of staple a half grade above the grades mentioned, the prefix “stnctly° is used. Quarter grades between the half grade and the next higher full grade are re ferred to as °barley° prefixed to the full grade term and the quarter grade below the half grade is designated by the prefix °fully° to the full grade below. As examples a staple graded as "barley middlings is a quarter grade below middling, "strict low is a half grade between middling and low middling and "fully low middling° is the quarter grade between the last and low middling, a full grade. This class ification is generally adopted in this country, while for Europe that of Liverpool is followed.
This differs from that of the New York Ex. change in being somewhat higher in the low grades and lower in the high grades. These classifications are based not only upon the length of staple, but its fineness, color, freedom from dirt, etc., and are more or less subject to differences in judgment, although little varia tion will be noticed in determining the quality of a sample when presented for sale.
Like every crop of wide cultivation many varieties of cotton have been produced and named. Some of these achieved a wide repu tation for some superior quality, flourished for a time and then disappeared. In 1880 the cen sus report named 58 well-known varieties, but in less than 15 years only six were still in common cultivation. In 1896, in a publication of the United States Department of Agriculture, more than 130 varieties were described, but within half a dozen years many of them had disappeared from seedsmen's lists. While par ticular varieties may cease of cultivation in a short time, the general type remains and types of cotton can now be readily recognized that have been in cultivation for more than half a century. The well-known tendency of the plant to vary is responsible for the production of so many varieties. There is perhaps no cultivated plant that responds so quickly to changed condi tions of soil, climate and cultivation as the cotton plant, and to this can be ascribed the improvement and deterioration of many vari eties. The most successful planters keep up the quality of their crop by continued selection of seed and for a crop that depends so much on the quality of the staple this is one of the most important considerations. The practice of planting seed purchased from gins and mills does more to depreciate the quality of the lint than any other factor.
Bibliography.— Balls, 'The Cotton Plant in Egypt' (London 1912) • Brooks,
Story of Cotton and the Development of the Cotton States' (Chicago 1911); Burkett,
(New York 1906) ; Dana, (Cotton from Seed to Loom' (London 1878) ; Dunstan,
and Reports on Cotton Cultivation> (ib. 1911) ; Henry, (Le coton dans l'Afrique Occidentale Francais0 (Paris 1906) ; Hohnel,
die Baumwolle) (Vienna 1893) ; Lecompte, (Le coton: monographic, culture, histoire econo mique (Paris 1900); Mallet,
The Chemical, Geological and Meteorological Con ditions for its Successful Cultivation' (London 1862) ; Miller,
Cotton System' (Austin, Tex., 1909); Monie,
Cotton Fibre: Its Structure' (Manchester 1890); Passon, (Die Kultur der Baumwollstaude> (Stuttgart 1910) ; Roux, (La production du coton en Egypte' (Paris 1908) ; Supf,
Colonial Reports, 1900-1908' (Berlin 1909) ; Todaro,