578 



STARCHES OP LILIACE^. 



The conspicuous forms are round, oval to ovoid, and transitional to clam-shell shape. When the 

 large, ovoid grains are viewed on edge, some appear to be rounded wedge-shaped and others flat- 

 tened ellipses, or somewhat lenticular. 



The hUum is a distinct, fairly large, round or oval spot, centric in the round forms and eccentric 

 about one-third to two-fifths of the longitudinal axis in the oval, ovoid, and mussel-shell-shaped 

 forms. Sometimes it is double. The hilum is rarely fissured, and the fissure is short, transverse 

 or longitudinal, clear-cut. 



The lainellce are fairly distinct, fine, regular, and complete. Those near the hilum are usually 

 circular, but as they are located nearer the margin they assume the form of the outline of the grain. 

 In the shell-shaped, ovoid, and oval grains the lamellae are usually more distinct near the margin 

 and at the distal end than near the hilum. A very few 

 at the distal end of the shell-shaped forms appear to be 

 incomplete. There are 10 to 14 on a single grain. 



The grains vary in size from 3 to 50/i. The common 

 size is 20 by 28/i in length and breadth. 



Polariscopic Properties. — The figure is slightly eccen- 

 tric or centric, distinct, and fairly clear-cut. Its lines are 

 rather thick and become thicker towards the margin. 

 They are usually straight, but sometimes slightly bent, 

 and occasionally bisected. 



The degree of polarization is high. It varies some- 

 what in different parts of the same grain, and is higher 

 when the grain is viewed on edge or end. 



With selenite the quadrants are fairly well defined 

 and are of about the same shape, but vary in size in some 

 forms. The colors are pure. 



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

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

 cent solution they color fairly and the color deepens rap- 

 idly. After heating in water until all the grains are com- 

 pletely gelatinized, the solution colors deeply and the grains deeply on the addition of iodine. After 

 boiling for 2 minutes the solution colors deeply and the grain-residues deeply or fairly. The cap- 

 sules color a reddish-violet on the addition of an excess of iodine. 



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

 and in 30 minutes they are fairly deeply stained. 



Temperature Reaction. — The temperature of gelatinization is 70° to 72° C, mean 71°. 



Effects of Various Reagents. — With chloral hydrate-dodine reaction begias in most grains in 45 sec- 

 onds, about three-fifths are gelatinized in 7 minutes, four-fifths in 15 minutes, and all in 20 minutes. 

 The reaction begins at the margin of the distal end, which darkens and swells very slightly, and 

 from this point the reaction spreads all around the margin and then inward until all of the grain 

 is affected. The grain does not swell very much until the starch of the inner portion reacts, when it 

 swells moderately. There did not appear to be any very sharp line of demarcation between the 

 gelatinized and ungelatinized portions of the grain during the progress of the reaction. The swollen 

 grains are fairly large, of a uniform dark color, and retain some of the original form. 



Reaction with chromic acid begins in some grains at once, in all in 15 seconds, and it is over in 

 3H minutes. The starch just above the hilum begins to pass into a gelatinous mass, and the rest of 

 the grain becomes divided by fine striae radiating from the hilum, which striae, as the grain swells, 

 become coarser and more distinct. The less resistant starch is gelatinized, while the more resistant 

 forms a broad band at the margin, which is striated and uneven on its inner border and shows the 

 remains of lamellae, especially at the distal end. Outside of this striated band there is a thin, trans- 

 parent envelope capsule which expands and becomes separated from the rest of the starch forming 

 the band. This capsule is dissolved at one point and the mass of the grain with its striated band 

 is partially extruded through this opening. The band also dissolves at one point, the gelatinized 

 starch flows out and is completely dissolved, and the rest of the capsule and band also dissolve later. 



The reaction with pyrogallic add begins at once and gelatinization is complete in 1)^ minutes. 

 The starch about the hilum is changed into a gelatinous mass, the lamellae grow indistinct, and the 



Curve of Reaction-Intensities of Starch of Muscari 

 botryoides. 



