620 



STAHCHES OF AMARYLLIDACE^. 



Curve of Reaction-Intensities of Starch of Amaryllis 

 belladonna major. 



The degree of polarization is high. There is a variation in the grains, some of the larger ones 

 having a very high polarization. Occasionally variations occur in the same aspect of a given grain. 

 AVith selenite the quadrants are sharply defined, unequal in size, and frequently irregular in 

 shape. The colors are usually pure, but occasionally they have a greenish tint. 



Iodine Reactions. With 0.25 per cent Lugol's solution the grains color a fairly dee]3 blue-violet 

 which deepens rapidly; with 0.125 per cent solution they color a very light violet, which deepens 

 rapidly. If the grains are heated in water until all are gelatinized and then treated with iodine, the 

 solution becomes a fairly deep indigo-blue and the grains a somewhat lighter blue. When the prepa- 

 ration is boiled for 2 minutes and then treated with 

 iodine the solution coloi-s a very deep indigo-blue and the 

 grain-residues a rather light, bright blue. With an excess 

 of iodine the grain-residues color a very deep blue and the 

 capsules either a deep reddish-violet or a deep heliotrope. 

 Staining Reactions. With gentian violet the grains 

 begin to color at once and in 30 minutes they are fairly 

 stained. 



With safranin the gi-ains color lightly at once and 

 in 30 minutes they are fairly deep in color, deeper than 

 with gentian violet. 



Temperature Reaction. The temperature of gelatin- 

 ization is 73 to 75 C, mean 74. 



Effects of Various Reagents. With chloral hydrate- 

 iodine the reaction begins at once. A few grains are gelat- 

 inized in a minute, about five-sixths in 2 minutes, and all 

 but a few resistant grains in 3 minutes. The reaction is 

 complete in all in 8 minutes. The grains color a deep old- 

 rose immediately, and a dark ring frequently appears at 

 the hilum. Gelatinization usually begins at the proxi- 

 mal end, accompanied by the formation of a small rounded protuberance colored a deep blue. 

 The same deep coloration now appears at the distal end and spreads around the margin. As the 

 two areas of gelatinized starch increase in size and approach each other, the ring formed at the 

 hilum end is forced slightly distalward and having enlarged, it collapses, one or more small bubbles 

 being ex])elled. The process of gelatinization and coloring now advances rapidly from both ends 

 towards the middle, a colorless line of demarcation between the gelatinized and ungelatinized starch 

 being demonstrable during the process. The gelatinized grains are deeply colored with light areas 

 at the hilum and fissm-es, and are much swollen, but retain the general shape of the untreated grain. 

 The reaction with chromic acid begins immediately. A few grains are dissolved in a minute, 

 nearly all in 2 minutes, and all but rare resistant grains in 3 minutes. The reaction is complete 

 in all in 43/2 minutes. The hilum swells and the lamellse become sliarply defined and striated. A 

 bubble frequently forms at the hilum, which quickly enlarges and collapses, followed by rapid swell- 

 ing at the proximal end. Delicate, short, radiating fissures pass from the hilum towards the proximal 

 end, and usually a fissm-e extends from each side of the hilum to the corners of the distal end, but 

 sometimes there is but one central, longitudinal fissure. Delicate lateral fissures extend from these 

 fissures, forming a feather-like figure, and gelatinization proceeds along the course of the fissures 

 until the greater part of the grain is broken down. Numerous delicate fissures pass from this gelat- 

 inized part to the distal end of the grain. The outer lamellse and the capsule at this point are 

 far more resistant than the rest of the grain. During gelatinization of the lamellse, refractive gran- 

 ules appear which persist in linear arrangement for a longer period at the distal end than at other 

 parts, but are fuially dissolved. The capsule at the proximal end ruj^tures, and about four-fifths of the 

 grain usually passes out and into solution about a minute before the distal end is finally dissolved. 

 The reaction with pyrogallic acid begins at once. A few grains are gelatinized in 30 seconds 

 and all in a minute, but the distal end of rare resistant grains in which the reaction is complete 

 may not be gelatinized until 2 minutes. The hilum or the margins of the cleft located at this region 

 swell, and the lamella; become sharply defined and striated. As a rule, a longitudinal fissure extends 

 from each side of the hilum to the corners of the distal end. At the hilum a bubble generally forms 

 and enlarges, and as the proximal end gelatinizes and swells the bubble is di-iven slightly distal- 



