648 STARCHES OF AMARYLLIDACE^. 



The reaction with chromic acid begins immediately. A few grains are dissolved in 30 seconds, 

 more than half in 2 minutes, nearly all in 4 minutes, and all but the more resistant parts of a few 

 grains in 5 minutes, which are usually dissolved in 6 minutes, rarely not until 9 minutes. The 

 lamellae become quite distinct and striated, the clefts at the hilum swell, and a bubble appears, 

 which enlarges gradually and then is expelled, followed quickly by gelatinization of this area. Usu- 

 ally either one longitudinal branched cleft, or many delicate radial fissures, according to the shape 

 of the grain, pass from this gelatinized area towards the sides and distal end, and the lamelhe (except 

 the outermost ones) become soluble, accompanied by the appearance of irregularly embedded, 

 refractive granules, which gradually pass into solution. The outermost lamellae, which are sharply 

 defined and striated, are comparatively resistant, but are finally dissolved. The grain continues 

 to swell until the capsule is ruptured either at the distal end or at any sharp corners which limit 

 this margin, and the entire grain gradually passes into solution. Grains in which the bubble at the 

 hilum becomes greatly enlarged are invaginated either at the proximal end or the sides nearby 

 during its expulsion, and the starch surrounding the gelatinized area is often cut into a sharp, 

 serrated lining, with brilliant refractive points. 



Reaction with pyrogallic acid begins immediately. A few grains are gelatinized in 15 seconds, 

 more than half in 30 seconds, nearly all in I3-2 minutes, and all but rare resistant grains in 2 minutes, 

 in which the reaction is complete in 3 minutes. The lamellae become distinct and striated, and the 

 clefts at the hilum swell, accompanied by the appearance of a bubble which is greatly enlarged 

 and then expelled. As the bubble disappears, usually a proximal or lateral invagination of the 

 grain occiu-s, followed by a recovery. The starch is quickly gelatinized, except the outermost lamellae, 

 in the greater part of which the reaction is later complete. The gelatinized grains are much swollen 

 and distorted. 



The reaction with /erne chloride begins in a few grains in 30 seconds. A small number are gelat- 

 inized in 2 minutes, about one-third in 5 minutes, about three-foiu-ths in 15 minutes, about nine- 

 tenths in 30 minutes, and all but rare resistant (one in many hundred) grains in 60 minutes. The 

 clefts at the hilum swell, and a small bubble appears which usually does not greatly enlarge. A lus- 

 trous border is formed around the grain, in which the lamellae are more sharply defined than in 

 other parts of the grain. Gelatinization usually begins at the distal end or at any sharp corners, 

 and soon spreads around the grain. The lustrous border increases in width, and when it reaches 

 the region of the hilum the bubble collapses, followed by the breaking of the most resistant starch 

 into usually two, sometimes more, large fragments, which gradually become gelatinized. The 

 gelatinized grain is much swollen and distorted. 



Reaction with Purdy's solution begins in a few grains at once. A few of the smaller grains 

 are gelatinized in 30 seconds, about one-seventh in 5 minutes, and about three-fifths in 15 minutes; 

 there is slight progress in 30 minutes, and about seven-tenths are gelatinized in 60 minutes. The 

 clefts at the hilum swell, a bubble sometimes appears, and the outer lamellae become sharply 

 defined and striated. There appears a large mesial cleft, from which delicate fissures radiate, 

 and gelatinization proceeds along the course of this cleft, frequently cutting the lamellsE into a sharp, 

 serrated lining having brilliant points. In some grains this lining is gradually gelatinized, but it 

 persists in others. Irregularly arranged, refractive granules usually appear, but are gradually gelat- 

 inized in most of the grains. The gelatinized grain is swollen, but is bounded by a firm, fairly 

 Ihick wall, and retains the general shape of the untreated grain. 



STARCH OF HYMENOCALLIS CALATHINA. (Plate 55, figs. 327 and 328. Chart 21!),) 



Histological Characteristics. In fortn the grains are usually simple, and isolated with the 

 exception of a small number which occur in small aggregates. There are a few compound grains 

 of few components. Irregular grains of similar character to those noted for H. undidata are found, 

 but are not so numerous nor so marked as in that species. The conspicuous forms are nearly round, 

 ellipsoidal, ovoid, dome-shaped, ellipsoidal with squared distal end, and somewhat bean-shaped; 

 also rounded triangular and quadrangular, lenticular, and polygonal. The forms are similar to 

 those found in H. undulata, but are more rounded or broader and less irregular. 



There is usually either a small, rounded cavity or a cleft at the hilum, but the hilum may be 

 observed as a clear round or elliptical spot, centric or eccentric, frequently about four-ninths, 

 rarely one-fourth, of the longitudinal axis. The clefts are similar to those noted for H. undulata. 



