THE GRAIN SORGHUMS 241 



remains, as it contains nearly all the fat. Polished rice con- 

 tains of digestible nutrients 4.6 per cent of protein, 72.8 pei 

 cent of carbohydates, and 0.4 per cent of fat. The by- 

 products of the mining industry are rice hulls, rice bran, 

 and rice flour or polish. Rice hulls are of httle value except 

 as fertilizer or mulch, for they contain a large percentage of 

 fiber and little nutriment. Rice bran and rice polish, how- 

 ever, are both valuable stock feeds. Rice straw is about 

 equal in feeding value to prairie hay, and is quite largely 

 used as rough feed for stock. It is also used to some extent in 

 the manufacture of straw hats, strawboard, and other articles. 



THE GRAIN SORGHUMS 



306. Origin and History. The sorghums which are 

 grown in various parts of the world for grain and forage for 

 the most part have been developed in Asia and Africa. A 

 large number of very diverse forms has been produced, 

 including the many sweet or forage sorghums, the grain- 

 bearing varieties such as kafir, milo, and durra, and the 

 fiber-producing type, represented by broomcorn. The grain 

 sorghums are important crops for the production of food for 

 man and animals quite generally in Africa, India, and por- 

 tions of China. Their cultivation in the United States 

 dates back only to about 1875, though some of the types had 

 doubtless been grown at an earlier period, but had disap- 

 peared from cultivation. 



307. Botanical Description. The various types of culti- 

 vated sorghums are all grouped by botanists under the head 

 of Andropogon sorghum. This original type is still found 

 quite generally in the warmer portions of the globe. In 

 general, the sorghums are large annual grasses with tall, 

 pithy stalks, growing from 4 to 10 feet high, and bearing the 

 seeds in a rather compact branching head or panicle. The 

 height of the stalk, the shape of the head, the size of the 

 seeds, and other characters are decidedly variable in the 



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