640 STARCHES OF AMARYLLIDACE^. 



a red-violet color when a slight excess of iodine is present. After boiling for 2 minutes the solution 

 colors deeply and most of the grain-residues not at all or lightly. With au excess of iodine the 

 capsules color a red-violet and a few of them contain blue-reacting starch at the proximal end. 



StaiJiiiKj Reactions. With gentian violet the grains begin to stain lightly at once and in 30 min- 

 utes are lightly stained, one as much as another. 



With safranin the grains begin to stain at once and in 30 minutes are rather lightly colored, 

 one as much as another. 



Tempef)-atxire Reaction. The temperature of gelatinization is 72 to 74 C, mean 73. 



Effects of Various Reagents. With chloral hydrate-iodine reaction begins in most grains in 2 

 minutes. It is complete in one-third in 25 minutes and in three-fourths in 50 minutes. The reaction 

 begins usually at the distal end; or if the grain has a longer transverse than longitudinal diameter, 

 it starts at the extremities of the transverse diameter, from which it usually proceeds all along the 

 margin, which becomes dark but does not swell, and then inward over the entire grain, the whole 

 grain swelling slightly. Occasionally the reaction originates at the extremities of the transverse 

 diameter, and then extends inward from both sides until the whole grain is involved without first 

 affecting the margin as a whole. The gelatinized grains are not very large, are of a uniform dark 

 color, and retain much of the original form. 



Reaction with chroviic acid begins in most grains in 30 seconds and in all in a minute, and is 

 over in 5J^ minutes. The reaction begins at the hilum, which swells slightly. Fine strite appear 

 throughout the grain, at fii-st distinguishable at the margin and later in the space about the swollen 

 hilum. The iimer portion of the grain is converted into a gelatinous mass, and the marginal part 

 forms a thick ring which is distinctly striated and sometimes shows alternate refractive and unre- 

 fractive rings of a lamellar arrangement. The grain increases in size in all directions, and the 

 marginal ring becomes very thin and transparent, and finally one point is dissolved, the inclosed 

 semifluid mass flows out and is dissolved, and the remaining part of the marginal ring dissolves 

 very soon afterward. 



The reaction with pyrogalUc acid begins in most grains in a minute and in all in IJ^ minutes. 

 About three-fourths are partially and one-fourth completely gelatinized in 4 minutes, and all are com- 

 pletely gelatinized in 35 minutes. The reaction begins at the hilum, which swells slightly, and fine 

 striae appear radiating throughout the grain. The inner part of the grain immediately surrounding the 

 hilum is transformed into a gelatinous mass and the remaining portion forms a very thick, striated, 

 marginal ring, which slowly becomes thinner and transparent as the grain swells slowly. The gelatin- 

 ized grains are large, somewhat wrinkled and sacculated, and do not retain the original form. 



Reaction with ferric chloride begins in a few grains in a minute. About three-fourths are com- 

 pletely gelatinized in 15 minutes, almost all in 30 minutes, and all in 40 minutes. The reaction 

 begins at the hilum in the small grains, but at the distal end in the larger grains. In the small 

 grains the hilum swells somewhat, fine strise appear throughout the grain, the more resistant starch 

 forms a tliick marginal ring, which is distinctly striated, and this ring becomes thin and trans- 

 parent as the grain swells and incloses a mass of gelatinized starch. The gelatinized grains so 

 formed are large and comparatively smooth and free from distortions. In the large grains the 

 distal end becomes fissured within the capsules in two or three places, and from these fissures the 

 gelatinized starch exudes, forcing out the capsule. This process of gelatinization involves the 

 entire mass at the distal end, and then moves proximally. In the meantime the same process 

 often starts at the jiroximal end, and from these two points the reaction proceeds over the whole 

 grain. When the reaction reaches a more resistant portion about the hilum this part becomes 

 divided by a fissure, and these two in turn into two, the foin- pieces gelatinizing independently 

 of one another. The gelatinized grains so formed are large;, wrinkled, and distorted. 



With Purdy's solution the reaction begins in many grains in a minute and a few are partially 

 gelatinized in 5 minutes. About half are partially and a few are completely gelatinized in 15 min- 

 utes and one-fourth are completely gelatinized in 30 minutes. The reaction is qualitatively the 

 same as that with pyrogallic acid. 



STARCH OF ZEPHYRANTHES ROSEA. (Plate 54, figs. 321 and 322. Chart 21.').) 



Histological Characteristics. In fortn the grains are simple and are isolated, except a few aggre- 

 gates in the form of tloublets. Pressure facets are rarely seen. There are no clumps. The surface 

 is smooth but somewhat irregular, owing to the unequal development resulting in small rounded 



