GENUS HEDYCHIUM. 



789 



The grains vary in size from 5 to 42/j. The dimensions of the clam-shell-shaped grains are on 

 an average 26 by 17^ in length and breadth, and those of the elliptical grains 36 by 28/i in length 

 and breadth. In the two forms the long and short diameters are reversed in relation to the longi- 

 tudinal and transverse diameters. The common size is about 28/i. 



Polariscopic Properties. — The figure is extremely eccentric, not distinct, and not clear-cut. 

 Usually only one and sometimes two lines are visible and they are usually broad and blurred, es- 

 pecially when near the margin, and sometimes bent and distorted. Rarely a grain is observed in 

 which all four lines of the figure are seen. 



The degree of polarization is very low, much lower than in the grains of H. curonarium. It 

 appears very high in the grains on end or edge, but does not vary much in different grains nor in a 

 given aspect of a grain. 



With selenite the quadrants are not well defined, are variable in shape and unequal in size. The 

 colors are not pure. 



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

 but not so deeply as the grains of H. coronarium; with 0.125 per cent solution the grains react 

 lightly at once and the color deepens somewhat. After heating in water until the grains are com- 

 pletely gelatinized, the solution colors rather lightly and 

 the grains very deeply with iodine. After boiling for 2 

 minutes the solution colors much more deeply and the 

 grain-residues less deeply. When an excess of iodine is 

 added most of the capsules show a dark-violet colora- 

 tion. The color is lighter than in H. coronarium. 



Staining Reactions. — ^With gentian violet and with 

 safranin the grains begin to stain at once and after 30 

 minutes are deeply stained. The color is slightly less 

 than that of H. coronarium. 



Temperature Reaction. — The temperature of gelatin- 

 ization is 70.2° to 72.1° C, mean 71.15°. 



Effects of Various Reagents. — With chloral hydrate- 

 iodine reaction starts in most grains in 15 to 30 seconds; 

 all are darkened in 3 minutes and the reaction is com- 

 plete in 45 minutes. The nipple-like projections and the 

 distal end darken and swell. These parts become joined 

 about the margin by progressive action, so that there is 

 formed a somewhat swollen gelatinous ring inclosing a 

 non-gelatinized center, which latter finally becomes in- 

 volved in the reaction. There is usually a sharp line of demarcation between the swollen and the 

 unswollen portions. The whole grain then swells until a fairly large, uniformly dark, gelatinous 

 mass is formed, which is somewhat distorted owing to the swelling and bending of the nipple-like 

 projections; otherwise the gelatinized grain retains much of the original form. 



With chromic add the reaction begins at once in most grains and is completed in 5 minutes. 

 The hilum becomes prominent and then swells. The portion of the grain between the hilum at the 

 distal end is divided by irregular fissures, then passes into a gelatinous mass. The grains continue 

 to swell, the capsule at the proximal end dissolves, the inner granular material flows out and is 

 dissolved, and then the rest of the capsule disappears. 



There is reaction with pyrogallic acid in one-fifth in a minute, but it apparently consists in 

 only a gradual fading of the lamellae, an increasing transparency of the grain, and occasionally a 

 slight swelling of the hilum and body of the grain. In about 25 minutes these grains show some 

 swelling and a partial gelatinization of the body of the grain. 



Reaction with ferric chloride is general in 30 seconds, and is over in 4 minutes. The reaction 

 consists in the swelling of the hilum and its protrusion as a more or less irregular projection from 

 the proximal end of the grain, usually accompanied by one or two similar protrusions from nearby 

 points. The body of the grain becomes divided by irregular fissures into granules which are trans- 

 formed into a gelatinous mass, and the whole grain swells. The gelatinized grains so formed are 

 large, lobulated, and irregular at the top, and folded in irregular lamella-like folds at the base. 

 They retain but little of the original form of the grain. 



Curve of Reaction-Intensities of Starch of Hedychium 

 gardnerianuin. 



