GENUS VICIA. 



383 



rounded comers, round, irregular heart-shaped, and triangular with rounded angles. There is a 

 larger proportion of rounded forms than in Vicia sativa. 



The hilu7n may be observed in the round or rounded grains as a clear, slightly refractive, round 

 spot that is located in a depression in the central part of the grain. In other forms the position of 

 the hilum is frequently marked by a deep fissure, which in the elongated grains extends along the 

 middle of the grain. This fissure may be clear-cut, but is more often ragged, and from it num- 

 erous lateral branches may proceed through the substance of the grain almost to the margin. 

 Often it is bisected at both ends. There is sometimes a central, non-lamellated, granular area 

 which is surrotmded by an irregularly branched, wreath-like fissure. 



The lamellw in the round forms are coarse, distinct, concentric rings. In the elongated grains 

 they are continuous, coarse bands which for the most part tend to follow the margin of the grain, 

 and therefore have the same irregularities as noted in the contour of the grain. They have the same 

 characters as recorded for V. sativa. They vary in number from 5 to 12. 



The grains vary in size from the smaller, which are 4 by 4/i, to the larger, which are 40 by 28ju or 36 

 by 20m in length and breadth. The common sizes are 27 by 23/i and 26 by 14/i in length and breadth. 



Polariscopic Properties. — The figure is centric or slightly eccentric, and in all essential respects 

 corresponds vnth that observed in V. sativa. 



The degree of polarization varies from high to very high. There is often a variation in the 

 same aspect of a grain. It is higher when the grain is viewed from the edge or end. It is higher and 

 there is greater range than in V. sativa. 



With selenite the peculiarities of the quadrants are essentially the same as those observed in 

 V. sativa. The colors are generally pure, but the yellow is sometimes not quite pure throughout 

 the entire quadrant. There is a slightly greater variation in the purity of the colors than in the 

 grains of V. sativa. 



Iodine Reactions. — With a 0.25 per cent Lugol's solution the grains color a fairly deep blue- 

 violet at once; with a 0.125 per cent solution they color a rather lighter violet, and the color deepens 

 fairly rapidly. The color of the grains is deeper than that 

 of V. sativa. After heating in water until all the grains 

 are completely gelatinized, the solution colors a greenish- 

 blue and the gelatinized grains a very deep reddish-blue 

 on the addition of iodine. After boiling for 2 minutes 

 the solution colors a deep indigo-blue, but most of the 

 grain-residues color very lightly. With an excess of 

 iodine the capsules become a deep reddish-purple. 



Staining Reactions. — With gentian violet the grains 

 begin to stain in a minute and in 30 minutes they are very 

 lightly stained. The stain is very slightly less than that 

 of V. sativa. 



With safranin the grains begin to stain at once and 

 in 30 minutes they are lightly stained. The stain is very 

 slightly less than that of V. sativa. 



Temperature Reaction. — The temperature of gelatin- 

 ization is 71° to 73° C, mean 72°. 



Effects of Various Reagents. — With chloral hydrate- 

 iodine the reaction begins in a few grains in 20 seconds. 

 About one-fifth are gelatinized in 5 minutes, one-half in 

 15 minutes, two-thirds in 30 minutes, and five-sixths in an hour 

 same as that of the grains of V. sativa. 



The reaction with chromic add begins in most of the grains in 15 seconds, and in all in a minute. 

 It is over in most of the grains in 1 minute and in all in 23^ minutes. It is the same qualitatively 

 as that of the grains of F. sativa. 



The reaction with pyrogaUic acid begins in most of the grains in 15 seconds and is over in all 

 in 1}4 minutes. It is the same qualitatively as that of the grains of V. sativa. 



With ferric chloride the reaction begins in a few grains in a minute. About one-half are com- 

 pletely gelatinized in 20 minutes and nearly all in an hour. The reaction is the same qualitatively 

 as that of the grains of V. sativa. 



PS CI PA CA 

 "" PC PS 



Curve of Reaction-Intensities of Starch of Vicia fulgens. 



The reaction is qualitatively the 



