COMMERCIAL FEEDING-STUFFS 



245 



the wheat kernel, tells us that the percentage propor- 

 tions of its various parts are as follows: 



Per cent 



Coatings 5 Starch cells 



Gluten layer 3-4 Germ . . 



Per cent 



84-86 

 6 



333. The milling of wheat. We are now prepared to 

 understand the significance of the statement that in mill- 

 ing wheat the flour of various grades comes from the 

 starch cells, the other 

 portions passing into 

 the bran, shorts, and 

 middlings, which col- 

 lectively are termed the 

 offal. If only the coat- 

 ings, gluten layer, and 

 germ went to make up 

 the offal it would in- 

 clude only about 14 or 

 15 per cent of the 

 kernel, the flours taking 

 the remainder, but, as 

 a matter of fact, no 

 milling methods so far 

 used completely separate the starch cells from the 

 inclosing tissue, so that the offal is perhaps never less 

 than 25 per cent of the whole grain. In milling tests con- 

 ducted by the Minnesota Experiment Station, the offal 

 from several lots of wheat, good and bad, varied from 

 25 to 40 per cent. If four bushels of wheat are consumed 

 per capita by the population of the United States, which 

 is below the estimate, and if only one-quarter of this is 

 converted into offals, the amount of bran and middlings 

 annually consumed by our domestic animals is not less 



FIG. 12. Partial scetion of wheat kernel 

 (enlarged 155 diameters). 1, seed pod; 

 2, outer seed coat; 3, inner seed coat; 

 4, gluten cells; 6, starch cells. 



