GENUS ANDROPOGON. 



361 



With pyrognllic acid the reaction bogiiis in some of the grains in 15 seconds and in tdl 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 quahtatively as that of the grains of 

 AVhite Kaffir corn. 



The reaction with Purdy's solution Ijcgins in a minute, but d(jes not advance ajjpreciably fur- 

 ther even in an hour. 



Differentiation of the Staixhes of the Genus Andropogon. 



Staining Reactions. 

 With Oentiau Violet. 



Histological Characteristics. 

 Conspicuous Forms. 



White Kaffir corn: Simple, few compound. Polygonal, 



round, rounded oval. 

 Yelhw Branching sorghum: Same as in White Kaftir corn. 

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



angular and varied in form. 



Hihim Form, Number, and Position. 



White 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. 



Yellnw Branching sorghum: Same a,s in Wliitc Kaffir corn. 



Shallu: Same as in White Kalfir corn. 



Lamellm General Characteristics. 



White Kaffir corn: Usually not visible. 



Yellow Branching sorghum: Usually not visible. 



Shallu: Usually not visible. 



Size. 



White Kaffir corn: From 2 to '2G/i, usually KIm. 



Yellow Branching sorghum: From 2 to 2i/i, usually IG/ji. 



Shallu: From 2 to 24/j, usually 15m. 



PoLAiuscopic Propektiks. 

 Figure. 



White Kaffir corn: Usu.ally centric, very distinct, fairly 

 clear-cut, regular, commonly straight. 



Yellow Branching sorghum: Same as in White Kaffir corn, 

 but the figure and lines are less often regular and 

 straight. 



Shallu: Same as Yellow Branching sorghum. 



Degree of Polarization. 



While Kaffir corn: High. 



Yellow Branching sorghum: High, slightly higher than in 



White Kaffir corn. 

 Shallu: High, same a.s in White Kaffir corn. 



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 corn, but less u-regular 

 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 ^\^lite Kaffir corn; violet. 

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



White Kaffir corn: Light. 



Yellow Branching sorghum: Light, slightly less than in 



White Kaffir corn. 

 Shallu: Light, less than in White Kaffir corn. 



With Safranin . 



White Kaffir com: Light. 



Yellow Branching sorghum: Light, slightly less than in 



V\'hite Kai^iir corn. 

 Shallu: Light, slightly less than in \Vhite Kaffir corn. 



TEMPERATtTRE OF GeLATINIZATION. 



While Kaffir corn: 07 to ("O" C, mean 68. 



Ydlow Branching son/hum: 09.1 to 70.8 C, mean 69.95. 



Shallu: 00 to 07 8 C., mean 66.9. 



Effects of Various Reagents. 

 Reaction with Chloral Hydrate-Iodine. 



While Kaffir corn: Begins in all in -15 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; coin])lete in nearly 



all in 15 minutes and in all in 20 minutes. 



Reaction with Chromic Aciil. 



White Kaffir corn: Begins in .some in 20 seconds; com- 

 plete in all in 2'^ minutes. 



Yellow Branching sorghum: Begins in some in 20 seconds; 

 complete in alt in 4 minutes. 



Shallu: Begins in all in ',iO seconds; complete in all in 3 

 minutes. 



Reaction with I'yrogallic .\cid. 



While Kaffir corn: 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 3J^ 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 1 J 2. 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 10 minutes. 



Reaction with Purdy's Solution. 



White Kaffir corn: 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. 



