542 STARCHES OP LILIACE^. 



protnision. The process extends inward over the whole grain, more rapidly along the margin on 

 each side than over the inner portion. There is a sharp line of demarcation between the gelatinized 

 and the non-gelatinized parts. The process in some grains starts from both ends and advances 

 from these points over the whole grain. The gelatinized grains are fairly large, somewhat distorted, 

 and usually uniformly dark. 



The reaction with chromic add begins at once and is over in a minute. The hilum becomes 

 very prominent and swells slightly, and the grain becomes covered by fine strise. The inner portion 

 is transformed into a gelatinous mass. The starch at the margin with some resistant starch of the 

 iimer portion forms a ring which is very distinctly striated and banded, more distinct at the distal 

 end than at the proximal end of the grain. The ring becomes thinner and transparent as the grain 

 continues to swell and finally ruptures at the proximal end, allowing the gelatinized starch within 

 to flow out and dissolve, the ring or capsule itself later completely dissolving. 



With pyrogalKc add most grains begin to react at once. All are fully gelatinized in 40 seconds. 

 Both hilum and lamellae are rendered very distinct. The hilum swells somewhat and the grain 

 becomes covered by fine strise. The inner portion is changed into a gelatinous mass. The starch 

 at the margin forms a ring which is striated, but not always distinctly banded. If the swelling 

 is very rapid, this ring may be divided at several places by very deep fissures which split it to the 

 capsule. This cleavage, when the grain is fully gelatinized, gives rise to a number of small saccula- 

 tions at the distal end. The gelatinized grains are large, somewhat folded and wrinkled, and often 

 irregular at the distal end. They do not retain much of the original form of the grain. 



With ferric chloride most grains begin to react in 1 J^ minutes. Nearly all are gelatinized in 10 

 minutes and all in 15 minutes. The hilum is rendered prominent, but not the lamellaj. The hilum 

 begins to swell and the grain is divided by fine radial striiB. The inner portion is changed to a 

 gelatinous mass. The marginal part forms a striated ring. This becomes thinner and more trans- 

 parent as the grain continues to swell, until finally a large, thin-walled mass is formed. The gelatin- 

 ized grains are large, fairly smooth, and somewhat distorted. 



Reaction with Purdy's solution begins at once in many grains, and about two-fifths are completely 

 gelatinized in 15 minutes, and nine-tenths in an hour. The hilum is very distinct, the lamellae are 

 visible, the hilum swells somewhat, and the grain becomes divided by fine strise. The inner portion 

 is transformed into a gelatinous mass as the grain swells. The marginal starch forms a ring which 

 is thicker at the distal end, where it shows fine striae and alternate refractive and non-refractive 

 bands. This ring gradually becomes thinner and more transparent until a large, fairly smooth 

 mass is formed. Some compound grains show a smaller mass within a larger one, showing that 

 there is here present a primary grain which has later become enveloped by a secondary grain. 



STARCH OF SCILLA PERUVIANA. (Plate 35, figs. 207 and 208. Chart 142.) 



Histological Characteristics. — In form the grains are usually simple. There are some very irreg- 

 ular compound grains which may consist of a variable number of components; also a few aggre- 

 gates composed either of grains of equal size, or of a large grain with several small grains adherent 

 to the distal end. The surface is somewhat varied, owing to lamellated additions made after the 

 original grain has been formed, or to protuberances caused by the unequal development. The 

 conspicuoas forms are rounded ovoid, or rounded elliptical with the larger proximal end and some- 

 what flattened distal end, or with both ends rounded; also round, ovoid, triangular, and quadrangular 

 forms, with rounded corners, and some irregular or incidental forms found in other Sdllos. The 

 grains are not flattened, and as a rule, when seen from the proximal end they appear spherical. 



The hilum is generally very distinct, comparatively small, and situated eccentrically about 

 one-fourth of the longitudinal axis of the grain. In some of the nearly round forms it is almost 

 centrically placed. It is usually to one side of the median line. Two or more hila are often placed 

 closely together, and in the compound grains each part has one or more hila. The hilum is usually 

 markedly fissured, and the fissures may be single, transverse, diagonal, or longitudinal; a straight 

 line, or a cross, or 3-armed, or irregularly stellate, and quite ragged. 



The lameUce are distinct, rather coarse lines, usually continuous, but which appear in compound 

 grains to become discontinuous near the margin of the original grain at the point where the lamellated 

 additions join it. They show no other irregularity in themselves, except that those of the original 

 grain are of different shape from those of the completed grain. They vary in size and distinctness 

 in diiferent grains, but not much in the same grain. There are about 14 to 20 on the larger grains. 



