666 



STARCHES OF AMARYLLIDACE^. 



may be separated from one another by small fissures, and one or all may be fissured. Sometimes 

 there is a long, curved, irregular fissure extending through the line of hila. The hilum is also not 

 infrequently of an elongated or lenticular form. 



The lameUce are distinct. They are rather fine, continuous rings, and tend to follow the outline 

 of the margin, which is often very irregular. One lamella near the hilum is usually more distinct 

 than the others. Those centrally located are almost always more distinct than those near the 

 margin. There are about 12 to 14 on the larger grains. 



The grains vary in size from 3 to 48^. The common size is 32;it. 



Polariscopic Properties. — The figure is usually eccentric, and not clear-cut, but distinct. One 

 or more of the lines are often quite broad, and sometimes not sharply defined. There is often 

 some slight bending or other distortion of the lines. 



The degree of polarization is high, varying greatly in 

 different grains; it is low or absent in some parts of the 

 grains, and in some grains only small marginal areas are 

 illuminated. 



With selenite the quadrants are usually not well 

 defined, are irregular in shape, and unequal in size. The 

 colors are sometimes pure. 



Iodine Reactions. — With 0.25 per cent Lugol's solu- 

 tion the grains are colored deeply a bluish-violet; with 

 0.125 per cent solution the grains tint lightly and the color 

 does not deepen very rapidly. After heating in water 

 until the grains are gelatinized, the solution is colored 

 deeply and the grains very deeply on the addition of 

 iodine. After boiling for 2 minutes the solution is colored 

 much more deeply, but the grain-residues much less. All 

 of the capsules contain some blue-reacting starch. With 

 an excess of iodine the capsules are colored a pinkish- 

 violet. 



Staining Reactions. — ^With gentian violet and with 

 safranin the grains begin to stain at once very lightly, and after 30 minutes are fairly stained. 



Temperature Reaction. — The temperature of gelatinization is 73° to 75° C, mean 74°. 



Effects of Various Reagents. — ^With chloral hydrate-iodine a few grains react in 23^ minutes, 

 and the reaction is general in 4 minutes. About one-fourth are darkened in 15 minutes, and all 

 are affected and four-fifths gelatinized in an hour. There was little further change. The hilum usu- 

 ally becomes prominent. The margin grows clearer and darker, and then irregular points on the 

 margin become very dark. This process may extend all around the margin or be confined to 

 the two ends of the grain or to irregular points on the side. It subsequently extends inward evenly 

 and without great swelling. The line of demarcation between the gelatinized and non-gelatinized 

 parts is fairly distinct. The gelatinized grains are not very large and are usually of a uniform color. 



With chromic add there is some reaction in 30 seconds, it is general in 13^ minutes, and 

 is over in 14 minutes. The hilum becomes distinct and then swells, and the grain is marked 

 by fine striae. The inner portion is changed into a thin, gelatinous mass, and the starch at the mar- 

 gin is formed into a saccular ring which is divided by coarse radial striae and presents a ragged 

 border on the inside. This ring or capsule grows thinner and clearer, and one part dissolves, fol- 

 lowed by an opening and the extrusion and solution of the contents, and the solution of the capsule. 



With pyrogallic add there is a very slight general reaction in 4 minutes. About one-fourth 

 of the grains are almost completely gelatinized in 25 minutes and about two-thirds are fully gelat- 

 inized in an hour. The hilum becomes distinct, but the lamellae are not especially so. The hilum 

 swells somewhat and the grain is divided by fine striae. The inner portion is transformed into a 

 gelatinous mass, while the margin becomes a thick, striated band which is very ragged on the inside. 

 This band or capsule becomes thinner, clearer, and quite homogeneous-looking as the grain swells. 

 The gelatinized grains are fairly large and somewhat wrinkled, but otherwise not greatly distorted. 



With ferric chloride there is a reaction in a few grains in 3 minutes and most of the grains 

 react in 10 minutes. A few are completely gelatinized in 10 minutes, about one-third in 15 

 minutes, and the reaction is complete in 13^ hours. The hilum becomes prominent and swells 



Curve of Reaction-Intensities of Starch of 

 Narcissus horsfieldii. 



