GENUS ZEA. 



353 



The hilum is centric or slightly eccentric, and when not fissured it appears as a rather indistinct, 

 small or largo round spot. In some grains there is a distinct, comparatively large, rovmd or irreg- 

 ularly shaped cavity. In many there is a single straight, narrow lino through the hilum, and in 

 others there is an arrangement of three lines proceeding from a common center. 



The lamellce are not demonstrable. 



The grains vary in size from the smaller, which are 3 by Zfx, to the larger, which are 20 by 20^. 

 The common size is 12^. 



Polariscopic Properties. The figure i.s usually centric, distinct, regular, and generally clear-cut. 

 The lines are for the most part straight, but may be curved and are sometimes broken, and tliey are 

 commonly placed at right angles to one another. 



The degree of polarization is high. It does not vary much in different grains nor in different 

 aspects of the same grain. It is much higher than in Golden Queen, slightly higher than in Stow- 

 ell's Evergreen, and distinctly higher than in Black Mexican. 



With selenite the quadi-ants are fairly well defined, usually irregular in shape, and commonly 

 unequal in size. The colors are purer than in Golden Queen and Stowell's Evergreen. 



Iodine Reactions. With a 0.25 per cent Lugol's solution the gi-ains all color a fairly deep violet; 

 with a 0.125 per cent solution they color very lightly. The shade is slightly more than in Golden 

 Queen and less than in Stowell's Evergreen. After heat- 

 ing in water until all the grains are completely gelatin- 

 ized, the solution colors fairly and the gelatinized gi-ains 

 very deeply on the addition of iodine. After boiling for 

 2 minutes the solution colors very deeply, but the gela- 

 tinized grain-residues not at all. The capsules all color 

 red-violet with an excess of iodine. 



Staining Reactions. With gentian violet the grains 

 stain very slightly at once, but after remaining in the solu- 

 tion for 30 minutes there is no further change. The color is 

 lighter than in Golden Queen and in Stowell's Evergreen. 



With safranin the grains stain unevenly and lightly 

 at once, but after remaining in the solution for 30 minutes 

 there is no further cliange. The color is less than in 

 Golden Queen and in Stowell's Evergreen. 



Tenipcrature Reaction. The temperature of gelati- 

 nization is 66 to 67 C., mean 66.50. 



Effects of Various Reagents. With chloral hydrate- 

 iodine the grains begin to react at once. Most are gela- 

 tinized in 30 seconds and a few scattered grains (one in 

 several hunthed) not until 10 minutes. The reaction is qualitatively the same as in Golden Queen. 



With chromic acid the reaction begins at once. Some grains are dissolved in 25 seconds and all 

 in 70 seconds. The reaction is qualitatively the same as in Goklen Queen. 



The reaction begins at once with pyrogallic acid. A few grains are gelatinized in 30 seconds 

 and all in a minute. The reaction is qualitatively the same as in Golden Queen. 



The reaction with feme chloride begins at once. A few grains are gelatinized in 132 minutes, 

 most in 4 minutes, and all with the exception of a few scattered grains (one in several hundred) 

 in 10 minutes. The reaction is qualitatively the same as in Golden Queen. 



With Purdy's solution the reaction begins at once. A few grains are gelatinized in 13^ minutes, 

 and about half in 30 minutes, but incomplete in an hour. The reaction is qualitatively the same as 

 in Golden Queen. 



Curve of Reaction-Intensities of Starch of Zea mays 

 var. saccharata (Golden Bantam). 



