OENUS TRITICtJM. 



.307 



Chart No. 



r.v s T C I 



a PA FC P S CI PA CA 

 PC PS 



With selenite the quadrants arc rarely well defined, and generally niicqual in size and irregular 

 in shape. The colors in the large grains are commonly not pure, and this lack of purity occurs in a 

 greater jiroportion of grains than in the previous i)reparation. 



Iodine Reactions. With a 0.25 per cent Lugol'-s solution the grains all color a fair hlue-violet 

 to reddish-violet; and with a 0.125 per cent solution they color lightly, and the culor deepens slowly. 

 Tilt? color is slightly deeper than that of tins grains of T. 

 solimim var. vulgare. After heating in ^^'ater until all the 

 gi-ains are completely g(>latinizod the solution colors fairly 

 and the gelatinizetl grains very deeply on the atklition of 

 iodine. After boiling for 2 minutes the solution colors 

 very deeply and most of the gelatinized grain-residues 

 very lightly. The capsules, which are much twisted and 

 folded, all color violet with an excess of iodine. 



Staining Reactions. With gentian violet the grains 

 begin to stain very lightly at once and in 30 minutes they 

 are very lightly stained. The color is the same as that of 

 the grains of T. sativum var. vulgare. 



With safranin the gi-ains begin to stain very lightly 

 at once and in 30 minutes they are lightly stained. The 

 color is the same as that of the grains of T. sativum var. 

 vulgare. 



Temperature Reaction. The temperature of gelatini- 

 zation is G2 to 03.8 C, mean 62.9. 



Effects of Various Reagents. With chloral hijdrate- 

 iudine the reaction begins in some of the grains in 15 to 

 45 seconds, and in most of the grains in 5 minutes. About one-fifth are fully gelatinized in 20 minutes, 

 without much further reaction in an hour. The reaction is the same qualitatively as that of the 

 grains of T. sativum var. vulgare. 



The reaction with chromic acid begins in from 10 to 20 seconds and is over in 2 minutes. It is 

 the same qualitatively as that of the grains of T. salirum var. vulgare. 



The reaction begins in 20 seconds and is over in 2 minutes with pyrogallic acid. 

 qualitatively as that of the grains of T. sativum var. vulgare. 



With ferric chloride the reaction begins in a few gi-ains in a minute. Nearly all are completely 

 gelatinized in 50 minutes and all in an hour. The reaction is qualitatively the same as that of the 

 grains of T. sativum var. vulgare. 



The reaction with Purdy's solution begins in some of the grains in 20 seconds, and in many in 

 a minute. About four-fifths are completely gelatinized in 5 minutes, nearly all in 10 minutes, ami 

 all in 15 minutes. The reaction is qualitatively the same as that of the grains of T. .sativum var. 

 vulgare. 



VL VL 80 



Curve of Reaction-Intensities of Starch of Triticum 

 sativum var. dicoccutn. 



It is the same 



Differentiation of the Starches of the Genus Triticum. 

 Histological CnAHACTERisTics. Histoloqical Characteristics. Continued. 



Conspicuous Forms. 



T. salinitn var. vulgare: Simple, large grains are nearly 

 round, oval, and irregularly ovoid; minute grains 

 globular and ovoid. 



T. salwum var. dicoccum: Same a.'" in T. sativum var. 

 vulgare, but minute grains are very much less 

 numerous and the larger grains vary more in form 

 and are more irregular in outline. 



Hiluni Form, Number, and Position. 



T. sativum var. vulgare: Form usually not vi.sible; in 

 large grains there may l)e a cavity or cleft and 

 occasionally radial fissures; in minute grains a 

 clear spot. Centric or slightly eccentric. 



T. sativum var. dicoccum: Same as in T. sativum var. 

 vulgare. Position (ciiliic or .slightly eccentric. 



Lamellce General Characteristics and Number. 



T. sativum var. vulgare: Rarely visible; fine, regular, 

 continuous rings. Occasionally 8 to 10 on the 

 larger grains. 



T. sativum var. dicoccum: Same as in T. sativum var. 

 tmtgare, but they are visible on a larger proportion 

 of grains. Occasionally 10 to 14 on the larger 

 grains. 



Size. 



T. sativum var. vulgare: From 2 to 3S;i, usually 20/i. 

 T. sativum var. diaiccum: From 2 to 40/j, usually 22^. 



PoLARiscopic Properties. 



Figure. 



T. sativum var. vulgare: Usually centric, commonly fairly 

 distinct, generally regular, lines usually straight. 



