808 STARCHES OF CANNACEiE. 



With selenite the quadrants are fairly well defined, fairly regular in shape, and very unequal 

 in size. The colors are usually not pure. 



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

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

 deeper than that of the grains of C. warszewiczii. After heating in water until the grains are com- 

 pletely gelatinized, the solution colors lightly and the grains fairly deeply on the addition of iodine. 

 After boiling for 2 minutes, the solution colors very deeply and the grain-residues lightly or not at 

 all. The capsules color a pinkish-violet with an excess of iodine; some retain blue-reacting starch 

 at the pro.ximal end. 



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

 minutes are deeply stained, some more than others. The color is the same as that of the grains of 

 C. warszewiczii. 



With safranin the grains begin to stain at once and in 30 minutes are deeply stained, some more 

 than others. The color is slightly less than that of the grains of C. tvarszewiczii. 



Temperature Reaction. The temperature of gelatinization is 69 to 71 C, mean 70. 



Effects of Various Reagents. With chloral hydrate-iodine reaction begins in 45 seconds. It is 

 complete in nearly all in 10 minutes and in all in 20 minutes. It is qualitatively the same as that 

 of the grains of C. ivarszewiczii. 



The reaction with chromic acid begins in 15 seconds and is over in 2J^ minutes. It is quali- 

 tatively the same as that of the grains of C. warszewiczii. 



The reaction with pyrogallic acid begins in a minute. All are partially and one-third com- 

 pletely gelatinized in 10 minutes, and about half are completely and the rest nearly completely 

 gelatinized in 15 minutes. The reaction is qualitatively the same as that recorded of the grains of 

 C. warszewiczii. 



Reaction with ferric chloride begins in some grains in a minute and is general in 23^ minutes. 

 Nearly all are gelatinized in 10 minutes and all in 23 minutes. The reaction is quahtatively the 

 same as that of the grains of C. ivarszewiczii . 



The reaction with Purdy's solution begins in a very few seconds and is over in 2 minutes. It 

 is the same qualitatively as that of the grains of C. warszewiczii. 



STARCH OF CANNA VAR. (J. D. EISELE). (Plate 85, figs. 509 and 510. Chart 344.) 



Histological Characteristics. In form the grains are simple, with the exception of a few com- 

 pounds which consist of two components. There are no aggregates, few clumps, and no pressure 

 facets. The surface of the grains is usually quite regular. There is slight irregularity of the margin 

 at the proximal end, owing to one- and two-sided slight depressions or to nodular or nipple-like projec- 

 tions. The most conspicuous form is the broad to flattened ovoid; also oval, elliptical, lenticular, 

 pyriform, triangular and quadrangular ^^^th rounded angles, almost round, clam-shell type, and 

 indefinite forms. The grains are much flattened and about one-fourth to one-half as thick as broad. 

 Usually the largest grains are one-half to three-fourths as broad as long. 



The hilum is sometimes invisible on account of an extreme marginal position. When seen it 

 is a fairly distinct, small, round spot, eccentric from the extreme margin to about one-sixth to one- 

 ninth of the longitudinal axis and in or near the median line. It is rarely fissured. The fissure is 

 a short, shallow, single, transverse line. There may be 2 or rarely more hila linearly arranged and 

 sometimes separated by fissures. 



The la7nell(e are very distinct, fairly regular circles in the region of the hilum, or arcs of circles 

 beyond, which are probably continuous. The arcs usually' follow the outline of the distal margin 

 but sometimes are wavy and otherwise irregular. They are generally arranged so that bands of 

 varying numbers of fine, not very distinct lamellae alternate with one or two very coarse, dis- 

 tinct lamellse. They vary in size and distinctness in the different grains and even in the same 

 grain are not so fine but usually more distinct near the distal end. There are about 55 on the 

 larger grains. 



The grains vary in size from 6 to 78^. The common size is 44;u. 



Polariscopic Properties. The figure is very eccentric, very distinct, but usually not clear-cut. 

 One or two long lines may be seen; if one line, it is usually in or near the longitudinal axis; if 

 two lines, they are oblique. Two lines may be connected by a transverse line at about two-thirds 

 of the distance from the hilum to the distal end. The lines are also often bent and vary in width. 



