743 



STARCHES OF IRIDACE^. 



Chart No. 288. 



I GV 

 S 



PS CI PA ( 

 ~ PC PS 



Curve of Reaction- Intensities of Starch of Antholyza 

 paniculata. 



STARCH OF ANTHOLYZA PANICULATA. (Plate 74, figs. 439 and 440. Chart 288.) 



Histological Characteristics. — In form the grains are simple, and are isolated except very few 

 aggregates of two or three components. The isolated grains are usually marked by one to three 

 pressure facets, commonly one or two. These facets are generally large and sharply defined, often 

 irregular in shape; there are many clumps and much foreign matter is present. The surface of the 

 grains is usually regular, but some irregularity may be due to a greater prominence of one side of 

 the distal end than of the other. The conspicuous forms are the spherical, hemispherical, and 

 rounded ovoid; the hemispherical forms have from one to three or more facets at the base or distal 

 end. There are also the elliptical and rounded triangular 

 forms of the doublets and triplets. Some of the medium- 

 sized and small grains are polygonal, owing to multiple 

 pressure facets. The grains are not flattened, and appear 

 spherical when seen on end. 



The hilum is not very large. It is a fairly distinct 

 roimd spot or cavity, usually eccentric about two-fifths 

 or less of the longitudinal axis; sometimes marked by a 

 rather short, straight, transverse fissure. 



The lameUcR are fairly distinct, usually coarse, and 

 regular continuous rings when near the hilum, but when 

 near the margin they may be irregular and discontinu- 

 ous rings. They are coarser and more distinct near the 

 hilum than near the margin of the grain. There are 10 

 to 12 on the larger grains. 



The grains vary in size from 0.75 to 30 by 17ai in 

 length and breadth. The common size is 20 by 16fi in 

 length and breadth. 



Polariscopic Properties. — The figure is usually eccen- 

 tric, distinct, and generally clear-cut. At times its lines 

 become less clearly defined in some portions of their length. They are sometimes curved and other- 

 wise distorted and as a rule are broader near the margin of the grains. In the faceted grains another 

 figure or parts of a figure may be seen on the faceted surface, and in the doublets or triplets a cor- 

 responding number of figures may be seen. 



The degree of polarization is fairly high. It varies much in different grains, but not much in 

 different aspects of the same grain. In the same aspect of a grain it is sometimes lower at the facets 

 than in other parts. It is not so high as in ^. crocosmoides. 



With selenite the quadrants are generally fairly well defined, irregular in shape, and unequal 

 in size. The colors are fairly pure. 



Iodine Reactions. — ^With 0.25 per cent Lugol's solution the grains color alight blue-violet; with 

 0.125 per cent solution they do not color for IJ^ minutes and then lightly. The color is even lighter 

 than that of the grains of A. crocosmoides. After heating in water until the grains are completely 

 gelatinized, the solution colors deeply and the swollen grains very deeply. After boiling for 2 min- 

 utes the solution colors very deeply and the grain-residues fairly. On the addition of an excess of 

 iodine most of the capsules color violet. 



Staining Reactions. — With gentian triolet and with safranin the grains begin to stain at once 

 and in 30 minutes stain fairly, some more than the rest. The stain is less than that of A . crocosmoides. 



Temperature Reaction. — The temperature of gelatinization is 71° to 73° C, mean 72°. 



Effects of Various Reagents. — With chloral hydrate-iodine reaction begins in some grains in 30 

 seconds and in most in IJ^ minutes. About four-fifths are affected in 10 minutes. The reaction is 

 incomplete in an hour and is the same qualitatively as that of the grains of A. crocosmoides. 



The reaction with chromic add begins in some grains in 30 seconds and in all within 45 seconds, 

 and is over in all in 2 minutes. It is the same qualitatively as that of the grains of A. crocosmoides. 



Reaction with pyrogallic acid has begun in all the grains in 45 seconds and is over in 33^ min- 

 utes. It is the same qualitatively as that of the grains of A. crocosmoides. 



The reaction with /emc chloride begins in some grains in 2 minutes and is over in all in 23 min- 

 utes. It is the same qualitatively as that of the grains of A . crocosmoides. 



