GENUS ANDROPOGON. 



361 



With pyrogallic add the reaction begins in some of the grains in 15 seconds and in all in 45 sec- 

 onds. It is over in 3 minutes. It is the same qualitatively as that of the grains of White Kaffir corn. 



The reaction begins in some of the grains in 45 seconds with ferric chloride. It is over in most 

 of them in 7 minutes and all in 15 minutes. It is the same qualitatively as that of the grains of 

 White Kaffir corn. 



The reaction with Purdy's solution begins in a minute, but does not advance appreciably fur- 

 ther even in an hour. 



Differentiation of the Starches of the Genics Andropogon. 



Staining Reactions. 



With Oentian Violet. 



White Kaffir com: Light. 



Yellow Branching sorghum: Light, slightly leas than in 



White Kaffir corn. 

 ShaUu: Light, less than in White Kaffir com. 



Histological Chakacteristics. 

 Conspicuous Forms. 



White Kaffir com: Simple, few compound. Polygonal, 



round, rounded oval. 

 Yellow Branching sorghum.: Same as in White Kaffir com. 

 Shallu: Same as in White Kaffir corn, but rather more 



angular and varied in form. 



HHum — Form, Number, and Position. 



While Kaffir com: Form fairly distinct, round; sometimes 

 more than one hilum; a spot or usually a cavity; 

 often fissured, clefts usually form a cross or a 

 3-armed figure. Position centric or slightly 

 eccentric. 



Yellow Branching sorghum: Same as in White Kaffir corn. 



Shallu: Same as in White Kaffir com. 



Lamelloe — General Characteristics. 



While Kaffir corn: Usually not visible. 



Yellow Branching sorghum: Usually not visible. 



Shallu: Usually not visible. 



Size. 



While Kaffir com: From 2 to 26/i, usually 16/i. 



Yellow Branching sorghum: From 2 to 24/i, usually 16/i. 



ShaUu: From 2 to 24^11, usually 15m. 



PoLAEiscopic Properties. 

 Figure. 



White Kaffir com: Usually centric, very distinct, fairly 

 clear-<;ut, regular, commonly straight. 



Yellow Branching sorghum: Same as in White Kaffir corn, 

 but tlu! figure and lines are less often regular and 

 straight. 



Shallu: Same as Yellow Branching sorghum. 



Degree of Polarization. 



White Kaffir corn: High. 



Yellow Branching sorghum: High, slightly higher than in 



White Kaffir com. 

 Shallu: High, same as in White Kaffir com. 



Polarization with Selenite — Quadrants and Colors. 



White Kaffir corn: Quadrants well defined, usually irreg- 

 ular in shape and unequal in size. Color pure. 



Yellow Branching sorghum: Quadrants same as in While 

 Kaffir corn, but vary more in size and shape. Color 

 pure. 



Shallu: Same as in White Kaffir com, but less irregular 

 in size and shape. Color pure. 



Iodine Reactions. 



Intensity and Color. 



White Kaffir corn: Fairly deep; violet. 



Yellow Branching sorghum: Fairly deep, slightly less than 



in White Kaffir corn; violet. 

 Shallu: Fairly deep, same as in White Kaffir com; violet. 



With Safranin. 



While Kaffir com: Light. 



Yellow Branching sorghum: Light, slightly less than in 



White Kaffir corn. 

 Shallu: Light, slightly less than in White Kaffir com. 



Temperature of Gelatinization. 



While Kaffir corn: 67 to 69° C, mean 68°. 



Yellow Branching sorghum: 69.1 to 70.8° C, mean 69.95°. 



Shallu: 66 to 67 8° C, mean 66.9°. 



Effects of Various Reagents. 

 Reaction with Chloral Hydrate-Iodine. 



While Kaffir corn: Begins in all in 45 seconds; complete 



in nearly all in 8 minutes and in all in 15 minutes. 

 Yellow Branching sorghum: Begins in all in 45 seconds; 



complete in nearly all in 10 minutes and in all in 



15 minutes. 

 Shallu: Begins in all in 45 seconds; complete in nearly 



all in 15 minutes and in all in 20 minutes. 



Reaction with Chromic Acid. 



While Kaffir com: Begins in some in 20 seconds; com- 

 plete in all in 2}-^ minutes. 



Yellow Branching sorghum: Begins in some in 20 seconds; 

 complete in all in 4 minutes. 



Shallu: Begins in all in 30 seconds; complete in all in 3 

 minutes. 



Reaction with Pyrogallic Acid. 



While Kaffir com: Begins in all in 30 seconds; complete 



in all in 2 minutes. 

 Yellow Branching sorghum: Begins in all in 30 seconds; 



complete in all in 3}^ minutes. 

 Shallu: Begins in all in 45 seconds; complete in all in 



3 minutes. 



Reaction with Ferric Chloride. 



White Kaffir corn: Begins in many in 1 minute; complete 

 in most in 10 minutes and in all in 20 minutes. 



Yellow Branching sorghum: Begins in some in IJ^ min- 

 utes; complete in most in 10 minutes and in all 

 in 15 minutes. 



Shallu: Begins in some in 45 seconds; complete in most 

 in 7 minutes and in all in 16 minutes. 



Reaction with Purdy's Solution. 



White Kaffir com: Begins in some in a minute; no further 



progress in an hour. 

 Yellow Branching sorghum: Begins in some in a minute; 



no further progress in an hour. 

 Shallu: Begins in some in a minute; no further progress 



in an hour. 



