664 



STARCHES OF AMARYLLIDACE^E. 



P 1 GV T P 



Chart No. 227. 



GV 3 T CI CA PA FC P S CLPA CA 



GENUS STERNBERGIA. 



Sieriibergia includes only four species of bulbous plants, natives of Eastern Europe to Asia 

 ]\Iinor. Starch was obtained from S. lutea Ker-Gawl. (Amaryllis lutea Linn.), a native of the Med- 

 iterranean region of Europe, and of Asia, and popularly kno\vn as the star-flower and winter daffodil. 



STARCH OF STERNBERGIA LUTEA. (Plate 58, figs. 343 and 344. Chart 227.) 



Histological Characteristics. In form the grains are usually simple, vnth very few compounds 

 and a few aggregates. No pressure facets were observed on the isolated grains, and no clumps. 

 The surface of the grains is usually very irregular, owing to unequal development, which results in 

 numerous more or less nodular elevations and depressions. The conspicuous forms are ovoid, 

 oval, round, ellipsoidal, reniform, and various irregular shapes. Many grains are as thick as broad, 

 but some of the larger are about one-half to two-thirds as thick as broad. 



The hilum is a distinct, rather small, round or lenticular spot, usually eccentric about two- 

 fifths of the longitudinal axis, and in or to one side of the median line. Sometimes two or more 

 hila occiu' in a single grain. The hilum is sometimes fissured, and there may be either a single 

 clean-cut, short, transverse, diagonal or longitudinal fissure; or two short, narrow, clean-cut fissures 

 forming a cross. 



The lamellce are distinct, rather coarse, continuous, irregular rings, which tend even when near 

 the hilum to follow more or less closely the outline of the margin. They are usually coarser and 

 more distinct near the margin than near the hilum. They vary in size and distinctness in different 

 grains and in different parts of the same grain. There are 

 G to 8 on the larger grains. 



The grains vary in size from 6 to 50/i. The common 

 size is 34/i. 



Polariscopic Properties. The figure is usually eccen- 

 tric, fairly distinct, irregular, and seldom clear-cut. The 

 lines are often bent or otherwise distorted, or bisected, 

 and placed at widely varying angles to one another. 

 Double figures are seen occasionally. 



The degree of polarization is fairly high. It varies 

 somewhat in different grains, in different aspects of the 

 same grain, and in different parts of the same aspect of 

 a grain. 



With selcnite the quadrants are fairly well defined, 

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

 never pure. 



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

 tion the grains color a deep blue-violet; with 0.125 per 

 cent solution they color rather lightly at first and the 

 color quickly deepens. After heating in water until the 

 grains are completely gelatinized, the solution colors lightly and the grains very deeply on the addi- 

 tion of iodine. After boiling for 2 minutes the solution colors deeply and the grain-residues lightly 

 or commonly not at all. The capsules color a red-violet with excess of iodine. 



Staining Reactions. AVith gentian violet the grains begin to stain very lightly at once and in 

 30 minutes are fairly stained, one grain as much as another. 



With safranin the grains begin to stain at once and in 30 minutes are deeply stained, one grain 

 as much as another. 



Temperature Reaction. The temperature of gelatinization is 75 to 7G C, mean 75.5. 



Effects of Various Reagents. With chloral hydrate-iodine reaction begins in most grains in Ij^ 

 minutes. About half are gelatinized in 18 minutes, three-fourths in 50 minutes, and four-fifths in 

 70 minutes. The reaction begins at the sides, which become dark. Then the starch at both distal 

 and proximal ends grows darker and swells somewhat, and from these two points this process of 

 swelling and coloring extends inward until the entire grain is affected. The gelatinized grains are 

 not very large and are of uniform dark color. They are somewhat distorted, but retain some of 

 the original form. 



Curve of Reaction-Intensities of Starch of 



Sternbergia lutea. 



