BY-PRODUCTS OF COTTON 215 



of the plant. The proportion of seeds in lock-cotton is usually 

 about two-thirds of the total weight. 



Fertilizing Constituents in the Seed. The seeds of cotton, un- 

 like the fiber, are rich in fertilizing constituents. In 1000 pounds 

 of seeds, which is approximately the complement of 500 pounds of 

 lint, there are the following amounts of plant food elements : 



Nitrogen 31 pounds 



Phosphoric acid 13 pounds 



Potash 12 pounds 



Lime 2.5 pounds 



Covering of the Seed. Beneath the long fibers, the seeds (Fig. 

 83) of most upland varieties are densely covered with a short fuzz, 

 which may, according to the 

 variety, be gray, green, or brown. 

 However, there are a few 

 varieties the seeds of which are 

 almost free from this cover- 

 ing. The Peterkin variety, 

 which has naked brown or black 

 seeds, is a notable example of 

 this type. In Sea Island cotton, 

 also, the seeds are nearly or quite 

 naked after the long fibers are 



FIG. 83. Showing two types of cotton 



removed. seed: A, seeds with a short, fuzzy cover- 



TT , . , . -r, , ing; B, smooth, or naked seeds. 



Weight Per Busliel. The 



legal weight of a bushel of seeds is usually either 33 or 33% pounds, 

 although naked seeds, that is, those lacking the fuzzy covering, are 

 several pounds heavier. The naked, smooth, Sea Island seeds usually 

 weigh about forty-four pounds per bushel. 



Structure of the Seed. The general structure of a cotton seed 

 is very simple. There are only two main parts the rough outer 

 hull, or seed-coat, and the kernel. The kernel is somewhat shrunken 

 and is easily removed from the hull. It consists mainly of two fleshy 

 seed leaves folded around the embryo, or young plant. From the 

 seeds are derived the valuable by-products of the cotton erop feeds, 

 fertilizer, and oil. 



By-products of Cotton. The products of the cotton plant do 



