630 



STARCHES OF AMARYLLIDACE^. 



Curve of Reaction-Intensities of Starch of 

 Hippeastrum cquestre. 



Iodine Reactions. With 0.25 per cent Lugol's solution the grains color a very deep indigo; 

 and with 0.125 per cent solution they color fairly well at once and the color deepens rapidly. The 

 color is slightly deeper than that of the grains of H. vittaturn. After heating in water until the grains 

 are completely gelatinized, the solution colors fairly and the grains deeply on the addition of iodine. 

 After boiling for 2 minutes the solution colors deeply, but most of the grain-residues not at all. 

 With an excess of iodine the capsules color a red-violet. 

 Many of the capsules are disintegrated. 



Staining Reactions. With gentian violet the grains 

 begin to stain very lightly at once and in 30 minutes are 

 fairly deeply stained. The color is less than that of the 

 grains of H. vitlalum. 



With safranin the grains begin to stain at once and 

 in 30 minutes are fairly deeply stained. The color is less 

 than that of the grains of H. vittaturn. 



Temperature Reaction. The temperature of gelatin- 

 ization is 72 to 73 C, mean 72.5. 



Effects of Various Reagents. With chloral hydrate- 

 iodine reaction begins in most grains in a minute. About 

 one-third of the grains are gelatinized in 10 minutes, three- 

 fourths in 17 minutes, and four-fifths in 45 minutes. The 

 reaction is not complete in an hour. The reaction is quali- 

 tatively the same as that of the grains of H. vittaturn. 



The reaction with chromic acid begins in some grains in 

 15 seconds, in all in 45 seconds, and is over in 6 minutes. It 

 is qualitatively the same as that of the grains of H. vittaturn. 



Reaction with pyrogallic add begins in some grains in 15 seconds and in all in 45 seconds. About 

 three-fourths are completely gelatinized in 3 minutes, almost all in 20 minutes, and all in 33 minutes. 

 The reaction is qualitatively the same as that of the grains of H. vittaturn. 



The reaction with ferric chloride begins in a few grains in a minute, 

 fourths in 18 minutes, in almost all in 30 minutes, and all in 48 minutes, 

 as that of the grains of H. vittaturn. 



Reaction ^^^th Purdy's solution begins in some grains in 30 seconds and in most grains in 15 

 seconds. About a third are partially gelatinized in 15 minutes, and half are partially and a few 

 completely gelatinized in 35 minutes, and one-fourth are completely gelatinized in IJ^ hours. The 

 reaction is the same qualitatively as that of the grains of H. vittaturn. 



STARCH OF HIPPEASTRUM AULICUM VAR. ROBUSTUM. (Plate 52, figs. 311 and 312. Chart 210.) 



Histological Characteristics. Inform the grains are usually simple. There are a few compounds 

 and a few aggregates. No pressure facets were observed on the isolated grains. There are no clumps. 

 The surface is somewhat irregular owing to unequal development and to the addition at different 

 periods of growth of groups of two or three or more discontinuous lamellae whose longitudinal axes 

 are at an angle to the longitudinal axis of the grain. At times two or more grains appear to have 

 been pressed together and both inclosed in several lamellae. Large doublets are occasionally seen. 

 The conspicuous forms are the spherical ovoid, which is narrower at the distal than at the proximal 

 end, and quadrilateral and triangular grains, whose corners are very much rounded off; also spherical, 

 slender elliptical, triangular, lenticular, pyriform, and some irregular forms. The grains are usually 

 as thick as they are broad, but some of the larger are from two-fifths to one-half as thick as broad. 



The hilum is a distinct, rather large spot, usually round, but sometimes lenticular. It may be 

 centric, but is usually eccentric about one-third to two-fifths of the longitudinal axis, and in or to 

 one side of the median line. There may be 2 or rarely more hila in one grain. The hilum is often 

 marked by a round cavity or a fissiu-e, which is usually a single, narrow, short line, commonly ragged 

 and irregular. It is sometimes broad and ragged, 3-armed, or variously irregular. 



The lamellae are very distinct, rather coarse, irregular, continuous rings, except near the margin, 

 where there may be one or more groups of discontinuous lamellae. They are usually coarser and 

 more distinct near the margin than near the hilum, and vary in size and distinctness in different 

 grains. There are about 10 to 12 on the larger grains. 



It is complete in three- 

 It is qualitatively the same 



