COMPOSITION OF RICE 



359 



sperm is quite hard, and is glassy or translucent, with only here 

 and there white or opaque spots. As in oats, the starch grains 

 are compound. The rice grains usually vary from three-eighths 



■9 



Longitudinal and cross section of rice kernel : I , cuticle ; 2, aleurone layer ; 3, endospernn 

 4, err.bryo; unnumbered lines show longitudmal depression in kernel. (After Dodson." 



to two-fifths of an inch in length. The w^eight of loo grains 

 may vary from two to three grams, or from 15,000 to 17,000 

 grains per pound. 



504. Composition. — The following table gives the average 

 of ten American analyses of clean rice, and one analysis each 

 of rough rice and rice straw : 



Rice 

 straw 



Water . 



Ash . . . 

 Protein (NX6.25) 

 Crude fiber . 

 Nitrogen-free extract 

 Fat . . . 



9.0 

 23.0 



4-7 

 32-3 

 32.1 



1.9 



Clean rice is characterized by high percentage of starch and 

 a correspondingly low percentage of other substances, especially 

 crude fiber. Over ninety per cent of the dry matter of rice is 

 nitrogen-free extract, almost exclusively starch. As a source of 

 easily digestible carbohydrates, rice is without a peer among 

 the cereals, and has few equals among food products. 



505. Varieties. — There are five types of rice, among which 

 ire lowland rice and upland rice. These have sometimes been 



