68 GRASSES OP IOWA. 



pound starch grains of Nardus in the tribe Hordeae are some- 

 what anomalous. 



Specific gravity. — Little work has been done in this country 

 on the specific weights of our seeds. Such studies have been 

 made of European wheat by Harz, Nobbe, Koernicke and Wer- 

 ner and others. Several years ago Paramel and Stewart made 

 some determinations indicating the difference in wheat in this 

 respect and that a study of the specific gravity and number of 

 seed per pound and bushel of considerable interest and com- 

 mercial importance. 



Wolfenstein gives the following figures with reference to 

 wheat: 



Summer wheat, Halle, Germany 1.3884 



English wheat, England 1.4134 



Purple straw wheat, Australia 1 .4011 



Tuscan wheat, Australia 1. 4156 



Siberian wheat, Siberia 1.4149 



Michigan Amber, Michigan 1.4292 



Climate and soil both greatly modify the weight and charac- 

 ter of the seed. This variation is also great in different 

 varieties. To compare the results obtained from these studies 

 a few figures are taken from Harz. One hundred seeds of the 

 following varieties weighed as follows: Prince Albert, 5.102 

 grams; Archer's Prolific, 4.298 grams; Hunters wheat, 3.714 

 grams; Mediterranean wheat, 4.532; White Genesee wheat, 

 4.403 grams. 



Some tests made by Pammel and Stewart* with wheat from 

 various localities in the United States gave the following 

 results: World's Fair, Seneca Falls, N. Y., 1.146296; Winter 

 Fife, La Crosse, Wis., 1.44578; Martin Amber, La Crosse, 

 Wis., 1.35054; Golden Cross No. 2, 1.47524; Bissell, Manhat- 

 tan, Kan., 1.4765; Turkey Red, Manhattan, Kan., 1.441; Mis- 

 sogen, Berkley, Cal., 1.480; Carter's Hundredfold, Berkley, 

 Cal,, 1.518; Fultz, Raleigh, N. C, 1.489; Red May, Raleigh, 

 N. C, 1.454; Turkey Red, lo.va, 1.43727. According to Wolf- 

 enstein, as quoted by Nobbe, the lowest specific gravity out of 

 the thirty samples, occurs in white wheat (Saxony), 1.3766. 

 An average sample of Bohemian wheat from the market, con- 

 sisting of three varieties had a specific gravity of 1.4208. 

 The highest specific gravity recorded is 1.4396, Ohio Red. 



* Bull. la. Agrl. Exp. Sta. 35: 28. 



