REQUIREMENTS FOR SOUNDNESS 11 



1,5 to 6 per cent; large amounts of starch, 45 to 65 per cent; and com- 

 paratively little mineral matter, 2 per cent in decorticated grains and 4 

 per cent in whole grains with the glumes. Potash and phosphoric 

 acid predominate among the salts, while lime is present in very small 

 amount, 0.05 per cent. 



In the structure of the grain (see Fig. 34) we distinguish: 



1. The seed coat, composed of an inner and an out layer. The 

 nutritive valu?. and digestibility of the seed coat correspond approxi- 

 mately to those of the glumes or chaff. 



2. The body of the grain, or endosperm. The endosperm consists 

 of an outer layer of cells rich in albumen, the aleurone layer, which in- 

 closes the endosperm proper (composed of starch-filled cells). 



3. The embryo, which is located at the base of the grain in a de- 

 pression in the endosperm and consists of cotyledon, stem and radicle. 



Samples for the examination or inspection of the quality of grain 

 should be taken from different depths and regions of the bin or sack 

 and thoroughly mixed. In Germany farmers may send such samples to 

 the agricultural experiment stations or to the hygienic institutes of 

 the veterinary colleges for grading. Each sample should consist of at 

 least two pounds of grain, carefully packed and sealed. In the grading 

 of grains and in the determination of their value the following points 

 are considered :^° 



1. Requirements for soundness. — The grain must be properly ma- 

 tured (shriveling indicates immaturity), have a natural gloss and a 

 sufficient degree of dryness, must not have a musty, moldy or other 

 foreign odor, must not show signs of germination, moldiness, nor be 

 spotty; not contaminated with injurious fungi (rust, ergot or smut); 

 contain no injurious insects, and no grains marked by weevils. Germi- 

 nated grains (Fig. 35) may be recognized by the three curly thread- 

 like rootlets at the base and, on section, the presence of a cavity which 

 contained the embryo. This cavity varies in size with the length of time 

 that the germinating process was active. Awns should not be mistaken 

 for, or confused with, the rootlets referred to (Fig. 36). This possi- 

 bility is greatest in awned oats. Most varieties of oats are unawned, 

 but the awned varieties have a slightly bent, bristly process about 1.5 

 to 2 cm. (3/5 to 4/5 in.) long, extending from the back of the outer 

 glume — the awn. 



2. Weight. — The weight of grain is determined either by weighing 

 a standard measured amount or by weighing a standard number of 

 grains, usually 100. Uniform size of the grain is a positive advantage 

 in weight. A liter of oats will weight 400 to 520 grams, medium grade 

 440 to 462 grams. For storage or elevator purposes the minimum weight 



lOFor official grain standards of the United States for wheat, corn and oats, see Service and 

 Regulatory Announcements, Bureau of Markets, U. S. Dept. of Agriculture, No. 33. There 

 are no United States Standards for rye. — Translator. 



