544 



STARCHES OF MLIACE^. 



PS Cl PA 

 ~ PC PS 



development. The conspicuous forms are ovoid to round, and irregular lenticular, some with almost 

 pointed projections on one side; also oval, elliptical, triangular with rounded corners, and various 

 irregular forms found in other Sdllce. The transverse diameter is longer than the longitudinal in 

 many of these grains, particularly the lenticular and the triangular. The grains are commonly 

 about two-thirds to three-fourths as thick as they are broad. 



The hilum is usually very distinct and is a comparatively large, round, non-refractive spot which 

 is eccentric commonly about one-foiu-th of the longitudinal axis of the grain. It may be in, near, 

 or very much to one side of the median line. It is rarely fissured, and the fissure in such cases is 

 very small and indistinct. It is often marked by a clean-cut, round, or somewhat elliptical cavity 

 which appears to communicate with the interior of the grain. There is often about the hilum a 

 well-marked area which appears to be raised above the surface of the rest of the grain and which 

 does not always have the same shape as the margin of the grain. There may be in a single grain 

 2 or more hila which usually are placed linearly in the direction of the transverse axis. The com- 

 pound grains show 2 or more hila, each surrounded by its own lamellae. 



The lamelloB are fairly distinct. They are rather coarse, continuous rings divisible into two 

 systems, those comprising the raised area about the hilum and those comprising the remainder of the 

 grain. Those of the first set are finer than those of the second. They vary in distinctness in different 

 grains. There are about 10 to 12 on the larger grains. 



The grains vary in size from 3 to 34/t. The common 

 size is 22m. The dimensions of an average ovoid grain are 

 20 by 24>x in width and length, and of the average trian- 

 gular or lenticular grain are 24 by 16m in width and length. 



Polariscopic Properties. — The figure is distinct, usu- 

 ally clear-cut, and eccentric. The lines may become 

 somewhat broader but less distinctly outlined as they 

 near the margin of the grain. They are somewhat bent 

 and otherwise distorted in some of the grains, of variable 

 width, and may be placed at varying angles. 



The degree of polarization is fairly high. It varies in 

 different grains and somewhat in different aspects of the 

 same grain. It is about the same or slightly higher than 

 that of the grains of S. sibirica. 



With selenite the quadrants are fairly well defined, 

 unequal in size, and usually irregular in shape. The 

 colors are not pure, except when the grain is viewed from 

 the top or side. 



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

 tion the grains are colored at once a deep blue- violet; with 0.125 per cent solution the grains color 

 lightly at first, and the color deepens rapidly. The shade is about the same as that of the grains 

 of S. sibirica. After heating until all the grains are completely gelatinized, the solution is colored 

 lightly and the gelatinized grains very deeply with iodine. After boiling for 2 minutes, the solution 

 is colored deeply and the grain-residues very lightly. The capsules all have a violet color after the 

 addition of a slight excess of iodine and most of them retain some blue-reacting starch. 



Staining Reactions. — With gentian violet some grains begin to stain at once and others in about 

 a minute. After 30 minutes the grains are but fairly stained, some more than others. The shade 

 is about the same as that of the grains of S. sibirica. 



With safranin the grains begin to stain at once, but some stain more deeply than others. After 

 30 minutes they are fairly deeply colored, some more than others. The shade is slightly deeper 

 than that of the grains of S. sibirica. 



Temperature Reaction. — The temperature of gelatinization is 64° to 65.5° C, mean 64.75°. 



Effects of Various Reagents.— With chloral hydrat-e-iodine about one-fourth of the grains begin 

 to react in 30 seconds, and the reaction is almost general in IJ^ minutes. About half are dark in 3 

 minutes and the reaction is complete in 15 minutes. This reaction is qualitatively the same as 

 that of the grains of S. sibirica. 



Reaction with chromic acid begins at once and is over in 2 minutes. This reaction is quali- 

 tatively the same as that of the grains of S. sibirica. 



MINUTES 

 Curve of Reaction-Intensities of Starch of Scilla bifolia. 



