354 



STARCHES OP GRAMINACEiE. 



Differentiation of the Starches of the Genus Zea. 

 Histological Characteristics. Histological Characteristics. — Continued. 



Conspicuous Forms. 

 Z. mays var. everta: 



Golden Queen. Simple, usually isolated, surface 



irregular, pressure facets common. Polygonal 



usually 4- to C-sided, oval and round to nearly 



round, both sometimes faceted. 



White lUce. Essentially thesameasin GoldenQueen. 



Z. mays var. indurata: 



North Dakota. Essentially the same as in Golden 



Queen. 

 Compton's Early. Essentially the same as in Grolden 

 Queen. 

 Z. mays var. indentala: 



Early Leaming. Essentially the same as in Golden 



Queen. 

 Hickory King. Essentially the same as in Golden 

 Queen. 

 Z. mays var. saccharata: 



Stowell's Evergreen. Essentially the same as in 



Golden Queen. 

 Black Mexican. Essentially the same as in Golden 



Queen. 

 Golden Bantam. Essentially the same as in Golden 

 Queen. 



Hilum — Form, Number, and Position. 



Z. mays var. everta: 



Golden Queen. Form small or large, round spot or 

 irregularly shaped cavity; commonly 3 small regu- 

 lar, narrow, radiating fissures. Position usually 

 centric, occasionally slightly eccentric. 



White Rice. Form essentially the same as in Golden 

 Queen. Position same as in Golden Queen. 

 Z. mays var. indurata: 



North Dakota. Form essentially the same as in 

 Golden Queen. Position same as in Golden Queen. 



Compton's Early. Form essentially the same as in 

 Golden Queen. Position same as in Golden Queen. 

 Z. mays var. iiidentata: 



Early Leaming. Form essentially the same as in 

 Golden Queen. Position same as in Golden Queen. 



Hickory King. Form essentially the same as in 

 Golden Queen. Position same as in Golden Queen. 

 Z. mays var. saccharata: 



Stowell's Evergreen, Form essentially the same as in 

 Golden Queen. Position same as in Golden Queen. 



Black Mexican. Form essentially the same as in 

 Golden Queen. Position same as in Golden Queen. 



Golden Bantam. Form essentially the same as in 

 Golden Queen. Position same as in Golden Queen. 



Lamdlm — General Characteristics, 



Z. mays var. everta: 



Golden Queen. Not demonstrable. 



White Rice. Not demonstrable. 

 Z. mays var. indurata: 



North Dakota. Not demonstrable. 



Compton's Early. Not demonstrable. 

 Z. mays var. indentala: 



Early Leaming. Not demonstrable. 



Hickory King. Not demonstrable. 

 Z. mays var. saccharata: 



Stowell's Evergreen. Not demonstrable. 



Black Mexican. Not rlemonstrable. 



Golden Bantam. Not demonstrable. 



Size. 

 Z. mays var. everta: 



Ciolden Queen. From 4 to IS/i, usually 12^. 



White Rice. From 4 to 17/i, usually 12^. 

 Z. mays var. indurata: 



North Dakota. From 2 to 22m, usually 12^. 



Compton's Early. From 4 to 22^, usually 14/i. 



Size. — Continued. 

 Z. mays var. indentala: 



Early Leaming. From 1 to 20(u, usually 14/j. 



Hickory King. From 2 to 16^, usually 8/j. 

 Z. mays var. saccharata: 



Stowell's Evergreen. From 4 to 20^, usually 14/x. 



Black Mexican. From 2 to 10^, usu.iUy 10^. 



Golden Bantam. From 3 to 20/j, usually 12/j. 



PoLARiscopic Properties. 

 Figure. 

 Z. mays var. everta: 



Golden Queen. Usually centric, sometimes slightly 



eccentric, distinct, fairly clear-cut, commonly 



regular, lines generally straight and at right angles. 



White Rice. Essentially the same as Golden Queen. 



Z. mays var. indurata: 



North Dakota. Essentially the same as in Golden 



Queen. 

 Compton's Early. Essentially the same as in Golden 

 Queen. 

 Z. mays var. indentala: 



Early Ijcaming. Essentially the same as in Golden 



Queen. 

 Hickory King. Essentially the same as in Golden 

 Queen. 

 Z. mays var. saccharata: 



Stowell's Evergreen. Essentially the same as in 



Golden Queen. 

 Black Mexican. Essentially the same as in Golden 



Queen. 

 Golden Bantam. Essentially the same as in Golden 

 Queen. 



Degree of Polarization. 



Z. mays var. everta: 



Golden Queen. Fairly high. 



White Rice. Fairly high, slightly less than in Golden 



Queen. 

 Z. mays var. indurata: 



North Dakota. Fairly high, slightly higher than in 



Golden Queen. 

 Compton's Early. Fairly high, higher than in 



Golden Queen, and the same as in North Dakota. 

 Z. mays var. indentala: 



Early Leaming. Fairly high, higher than in Golden 



Queen. 

 Hickory King. Fair, less than in Golden Queen, and 



not so high as in Early Leaming. 

 Z. mays var. saccharata: 



Stowell's Evergreen. High, higher than in Golden 



Queen. 

 Black Mexican. Low to fair, much le.ss than in 



Golden Queen, and much less than in Stowell's 



Evergreen. 

 Golden Bantam. High, much higher than in Golden 



Queen, slightly higher than in Stowell's Evergreen, 



and distinctly higher than in Black Mexican. 



Polarization with Selenite — Quadrants and Colors. 



Z. mays var. everta: 



Golden Queen. Quadrants usually well defined, 



irregular in shape, unequal in size. Colors usually 



pure. 

 White Rice. Quadrants the same as in Golden 



Queen. Colors usually jiure. 

 Z. mays v.ar. indurata: 



North Dakota. Quadrants not very well defined, 



fairly regular in form, usually equal in size. Colors 



usually pure. 

 Compton's Early. Quadrants essentially the same 



as in North Dakota. Colors usually pure. 



