436 Phytiicdl ('/Htr(icf( risfir.'< and Millinfi Qiidlitji 



the wheat kernel increased with the nitrofjen or protein content. 

 Marek^ states that in the samples examined by him a decrease in nitrogen 

 content was accompanied by an iiicrease in specific gravity. Kornicke 

 and Werner* state that the constituents of the wheat kernel have the 

 following specific gravity: starch, 1-53; sugar, 1-60; cellulose, 1-.53; 

 fats, ()■!)] -()•<»(); gluten, 1-297; ash, 2-50; air, 0-0()1293. They further 

 state that the volume weight bears no relation to specific gravity or to 

 protein content. Lloyd^ determined the weight per 100 kernels. volume 

 weight, and densities of wheats frf)m different parts of the world and 

 found Russian wheat to possess the lowest average weight per kernel, 

 and Australian wheat the highest. Wheat grown in the United States 

 and Canada had the highest average density or specific gravity, and that 

 grown in England the lowest. Pammel and Stewart* found the specific 

 gravity of wheat examined by them to range between 1-107 and 1-503. 

 Lyon^ states that wheat kernels having a high percentage of proteid 

 material have a lower specific gravity. His data (p. 57) indicate that 

 large kernels have a higher specific gravity than small kernels of the 

 same variety. Cobb® observed that there are fewer large starch 

 granules in wheats containing a low percentage of nitrogen. Lyon and 

 Keyser' confirmed Cobb's observations, and also found that large and 

 numerous vacuoles are associated in yellow-berry kernels. The differ- 

 ence in structure between horny and yellow-])erry kernels was also 

 accompanied by a difference in nitrogen, the yellow-berry kernels 

 containing less nitrogen than the horny. Roberts® states that the 

 presence of air vacuoles doubtless accounts for the lower specific gravity 

 of yellow-berry kernels. He later' presented the results of a number 

 of physical measurements of wheat kernels, including specific gravity. 

 The samples examined by him ranged in specific gravity from 1-218 to 

 1-38G. Willard and Swanson^" determined the specific gravity and other 

 factors of quality for Kansas, Minnesota, Tennessee, and Wasliington 

 wheats. They state (p. 81) that there is a tendency for large kernels 



' Miuek. Lundw. Zeit. J. Wcilfrikn ii Lippe, p. ."162, 187.5. 



= Kornicke and Werner. tJatuWuch d. Gelrcidebdues, Berlin, 1884. 



^ Lloyd. A7ner. Journ. Pharm. vol. LXVI. pp. 413-119, 1894. 



' Pammel and Stewart. Iowa Exp. Sla. Bill. No. 25, pp. 2(i :il, 1S94. 



' Lyon. U.S. Bur. Plant Iml. Bid. No. 78, 1905. 



" Cobb. Agr. Oitz. New Snitlli Wales, vol. xv. p. 512, 1904. 



' Lyon and Keyscr. Xehraska Exp. Sla. Bui. No. 89, 1905. 



» Koberts. Kan-ias Exp. Sla. Bui. No. 150, 1908. 



■' Koberts. Kaii.ias Exp. Sla. BuK No. 170, 1910. 



'" Willard and Swanson. Kansas Exp. Sla. Bui. No. 177. 1911. 



