country follows closely the mean summer temperature line of 77 degrees, and very little cotton is grown where there are less than 200 days without frost. There must be an annual rainfall of 23 inches. The cotton belt comprises chiefly eastern North Carolina, South Carolina, Georgia, northern Florida, Alabama, Mississippi, the western lowlands of Tennessee, Arkansas, Louisiana, Oklahoma, and eastern Texas; the densest areas are in the Piedmont Plateau and upper Atlantic Coastal Plain of South Carolina and Georgia, the Black Prairie of Alabama and Mississippi, the Yazoo Delta in northwestern Mississippi, the Red River Valley in Arkansas, and, most important of all, the Black Prairie of Texas. American upland cotton (G. hirsutum ) is almost exclusively planted over this area. More than 600 varieties have been named and described, which are divided into groups according to the size of the boll, the length of the staple, and earliness of fruiting. The big-boll group is the most popular and widely grown, since the cotton can be more easily and quickly picked.
The cotton plant has both floral and extra-floral nectaries. The floral nectaries consist of a narrow band of papilliform cells at the base of the inner side of the calyx. The five petals overlap except at base, where there are five small openings leading down to the nectar. These gaps are protected by long interlacing hairs which exclude insects too small to be of use as pollinators, but present no obstruction to the slender tongues of long-tongued bees and butterflies. There is also above the nectary a ring of straight stiff hairs pointing upward. Trelease saw the flowers visited by many bees, and Allard saw honeybees, bumblebees, and solitary bees (Melissodes) enter the corolla. After the flowers have changed in color from pale yellow to red, they cease to secrete nectar, and bees pay little attention to them.
The statement has been made that honeybees gather the surplus of cotton honey wholly from the leaf nectaries, but this is incorrect. Many beekeepers report that a large quantity of honey is gathered from the bloom. At Waxahachie, so little honey is gathered on the uplands until cotton blooms that it is necessary to feed the colonies. Late in the fall of 1909, at Trenton, Texas, cotton bloomed profusely from the middle of October until mid-November and two supers of honey were secured. The bees were laden with pollen as well as nectar and the queens laid as in the spring. Prominent beekeepers at Cordele, Georgia, and at Sulphur Springs, Arkansas, report that cotton blossoms yield a great amount of excellent honey.
There are two sets of extra-floral nectaries — the involucral nectaries and the leaf nectaries. Below the flower there are the three leaflike bracts called the involucre. At the base of each of these bracts there is a nectary both on the inner and outer side — six in all. The three inner involucral glands are situated between the calyx and the involucre, and are present both in the American and Asiatic species of cotton, but are sometimes absent in individual flowers. In form they are round, shield-shaped, or heart-shaped. The three outer involucral glands are at the base of the bracts on the outside. They are entirely absent in the Asiatic cottons. Greatly magnified, they strikingly resemble a shallow round dish with the bottom covered by a layer of large shot. According to Trelease the involucral nectaries secrete nectar abundantly, which in the daytime attracts bees, ants, and hummingbirds, and at night two species of moths.
The leaf nectaries are located on the under side of the main rib of the leaves, and vary in number from one to five. They are absent from individual leaves, and entirely wanting in Gossypium tomentosum. They are small pits, oval, pear-shaped, or arrow-shaped with long tails running down toward the base of the leaves. In the tropics they are soon overrun and blackened by a growth of mold. (Tyler, J. T. The Nectaries of Cotton, Bu. PI. Ind. Bull. 131, Pt. 5, 1908.) The leaf-glands seem to be most active at the time the leaf reaches full maturity. When the conditions are favorable nectar will collect on these glands in such large drops that it can be readily tasted and a bee can obtain its load in a very few visits. Honeybees then neglect the blossoms and honey comes in very rapidly. The honey secured