824 STARCHES OF COLCHICACE-Si. 



Staining Reactions. — With gentian violet the grains begin to stain very lightly in a minute and 

 in 30 minutes they are only very lightly stained. 



With safranin the grains begin to stain very lightly in a minute and in 30 minutes they are 

 lightly stained, some more than others. The grains color deeper with this stain than with gentian 

 violet. 



Temperature Reaction. — The temperature of gelatinization is 60.5° to 62° C, mean 61.25°. 



Effects of Variotis Reagents. — With chloral hydrate-iodine reaction begins in most grains in a 

 minute. About one-half are gelatinized in 5 minutes, almost all in 20 minutes, and all in 50 minutes. 

 The hilum, if not fissured, is visible, and if fissured it becomes very prominent. The edges and 

 comers of the facets at the distal end grow dark and begin to swell slightly, and this process extends 

 evenly upward over the whole grain, unaccompanied by very much swelling. There is usually a 

 fairly sharp line of demarcation between the reacting and the non-reacting parts. The gelatinized 

 grains are not very large, are uniformly dark in color, and retain much of the original form of the 

 grain, the main difference between the form of the normal and altered grains being in the greater 

 prominence of the corners of the facets of the latter. 



Reaction with chromic acid begins in 15 seconds in most grains and in all in 30 seconds, and is 

 over in 2 minutes. The hilum becomes prominent and begins to swell. Fine strise develop and 

 radiate from the hilum in all directions, and the inner portion of the grain is converted rapidly 

 into a gelatinous mass, the whole grain swelling, the expansion being greater at the proximal than 

 at the distal end. The marginal starch is formed into a thin, striated band which becomes thinner 

 and transparent, and is finally dissolved at the proximal end, allowing the inner, granular starch 

 to flow out and dissolve. Solution of the rest of the marginal band then follows. 



The reaction with pyrogallic acid begins in 30 seconds and is over in 13^ to 2 minutes. The 

 hilum, especially if fissiu-ed, becomes very prominent, and the lamellae become visible in some of 

 the grains. Then the hilum begins to swell and fine striae appear, which radiate in all directions. 

 The inner part of the grain is transformed into a gelatinous mass, and the marginal part is formed 

 into a thin ring, which is striated and shows several alternate refractive and non-refractive bands. 

 The proximal portion of the marginal band invaginates as the grain swells, and as swelling continues 

 and as the marginal ring becomes thinner and more transparent, this invagination is pushed out. 

 The gelatinized grains so formed are large and retain much of the original form, although they 

 are irregular and creased. 



Reaction with ferric chloride begins in 30 seconds in some grains and in l}/^ minutes in most 

 of them. About four-fifths are gelatinized in 12 minutes and all in 30 minutes. The hilum becomes 

 very prominent as a dark bubble and then begins to swell. The bubble first increases and then 

 decreases in size, and finally disappears. Fine striae appear radiating from the hilum in all direc- 

 tions. The portion of the grain-substance just about the hilum is gelatinized, and the remaining 

 part of the grain is completely divided by three or four internal or intracapsular fissures into parts, 

 each of which in turn may be divided, these several portions gelatinizing independently of one 

 another. The gelatinized grains do not retain any of the original form and usually are much folded 

 and wrinkled. 



The reaction with Purdy's solution begins in 30 minutes. About four-fifths are gelatinized in 

 17 minutes and all in an hour and 10 minutes. The reaction is the same qualitatively as that with 

 pyrogallic acid. 



