662 



STARCHES OF AMARYLLIDACE^. 



Chan No. 226. 



PC PS 

 6 



may appear to be segments of ellipses, which, however, are probably continuous. They are fine, 

 but generally more distinct near the hilum. There are about 12 to 14 on the larger grains. 



The grains vary in size from 18 to 69,u. The common size is 40/i. 



Polariscopic Properties. The figure is somewhat eccentric, distinct, regular, and fairly clear- 

 cut, though the lines become less well defined as they near the margin. The hues may bo very 

 broad, somewhat bent or othcrwse distorted in some part of their course. Double and multiple 

 figures are occasionally seen. 



The degree of polarization is very high. In some grains polarization colors are shown. It does 

 not vary much in different grains or in different aspects of the same grain. It is slightly higher than 

 that of the grains of A. ligtu. 



With selenite the quadrants are not sharply defined, are fairly regular in shape, but unequal in 

 size. The colors are not quite pure. 



Iodine reactions. With 0.25 per cent Lugol's solution the grains color a very deep blue-violet; 

 with 0.125 per cent solution they color fairly deeply and the color deepens rapidly. The color is 

 not so deep as in the grains of A. ligtu. After heating in water until the grains are completely gelat- 

 inized, the solution colors deeply and the grains fairly 

 deeply on the addition of iodine. After boiling for 2 

 minutes the solution colors more deeply, but most of the 

 grain-residues not at all. With excess of iodine the cap- 

 sules color a blue-violet and very few of them contain 

 blue-reacting starch. They are collapsed, broken, and 

 twisted. 



Staining Reactions. With gentian violet the grains 

 begin to stain at once and in 30 minutes are deeply 

 stained, some more than others. The color is slightly 

 deeper than the grains of A . ligtu. 



With safranin the grains begin to stain at once and 

 in 30 minutes are deeply stained, one as deeply as another. 

 The color is slightly deeper than in the grains of A. ligtu. 



Temperature Reaction. The temperature of gelatini- 

 zation is 53.5 to 56 C, mean 54.75. 



Effects of Various Reagents. With chloral hydrate- 

 iodine reaction is general in 30 seconds. About four-fifths 

 are gelatinized in 9 minutes and all in 17 minutes. It is the 

 same qualitatively as in corresponding grains of A. ligtu. 



The reaction with chromic acid begins in 15 seconds and is over in 1}4 minutes 

 qualitatively as in corresponding grains of A. ligtu. 



The reaction with pyrogallic acid is general in 30 seconds and is over in 4 minutes. It is the same 

 qualitatively as in corresponding grains of A. ligtu. 



Reaction with ferric chloride begins in some grains in 30 seconds. About four-fifths are gelat- 

 inized in 10 minutes and all in 20 minutes. Qualitatively the reaction is the same as in correspond- 

 ing grains of A. ligtu. 



The reaction with Purdy's solution begins in a very few seconds and is over in 30 seconds. It 

 is qualitatively the same as in corresponding grains of A. ligtu. 



Curve of Reaction-Intensities of Starch of Alstrcemeria 

 aurantiaca (aurea). 



It is the same 



Differentiation of Certain Starches of the Genus Alstroamcria. 



Histological Characteristics. 



Conspicuous Forms. 



A. ligtu: Usually compound or aggregates of 2, 3, or 

 more components. Ovoid, oval to elliptical. Sim- 

 ple grains spherical to ovoid, dome-shaped to hemi- 

 spherical. 



A. brasiliensis: Usually simple, few compounds, no aggre- 

 gates, or pressure facets of isolated grains. Ovoid, 

 spherical, oval to elliptical. 



A. aurantiaca (aurea) : Usuallysimple, few compounds and 

 aggregates, occasional grains with single pressure 

 facets. Ovoid to spherical, and oval. 



Histological Characteristics. Continued. 



Hilum Form, Number, and Position. 



A. ligtu: Form not distinct, small, round, often multiple; 

 sometimes fissured, fissures not large nor deep. 

 Position centric to eccentric about 0.40 of longi- 

 tudinal axis. 



A. brasiliensis: Form fairly distinct, small, round spot; 

 usually single, may be multiple; may be fissured, 

 fissures small but deep, and ragged. Position cen- 

 tric to eccentric about 0.40 to 0.16 of the longitudi- 

 nal axis; more eccentric, as a whole, than in the 

 other species. 



