GENUS CANNA. 



806 



aartNo. 341. 



P I GV 

 S 



PS CI PA I 

 ~ PC PS 



Reaction with pyrogallic acid begins in 45 seconds. Most grains are gelatinized in 6 minutes 

 and all in 12 minutes. It is the same qualitatively as that of the grains of C. warszewiczii. 



With ferric chloride a few grains begin to react in 45 seconds. Nearly all are gelatinized in 9 

 minutes and all in 15 minutes. The reaction is qualitatively the same as has been recorded in the 

 grains of C. warszewiczii. 



The reaction with Purdy's solution begins at once and is over in 40 seconds. It is the same 

 qualitatively as that of the grains of C. warszewiczii. 



STARCH OF CANNA VAR. (L. E. BALLY). (Plate 84, figa. 503 and 504. Chart 341.) 



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

 pounds. There are no aggregates, clumps, or pressure facets. The surface of the grains tends to be 

 quite regular excepting for slight depressions at the sides of the proximal end. The conspicuous 

 forms are the flattened, broad ovoid. There are also flat- 

 tened oval, oval, pyriform, lenticular, triangular and quad- 

 rangular with rounded angles, poorly formed clam-shell 

 type, and various irregular forms. The grains are all flat- 

 tened and about one-fourth to one-half as thick as wide, 

 and the larger grains are from three-fourths to as broad 

 as long. 



The hilum is a very eccentric and fairly distinct 

 small, round, or rarely lenticular spot. Eccentricity usu- 

 ally ranges from the extreme margin to from one-sixth 

 to one-ninth of the longitudinal axis of the grain. The 

 hilum lies in or to one side of the median line. It is never 

 fissured. There may be 2 or more hila linearly arranged. 



The lamella are distinct, fine circles about the hilum 

 or segments of circles, beyond which they are probably 

 continuous. They usually follow closely the outhne of the 

 distal end, but sometimes show waviness and other irregu- 

 larities not in accordance with the marginal outline. They 

 are usually so arranged that a band of fine lamellae alter- 

 nate with one large, coarse lamella. They are not so fine 

 but more distinct in some grains than in others and are commonly coarser though not necessarily 

 more distinct near the distal end. There are generally from 60 to 70 lamella on the larger grains. 



The grains vary in size from 6 to 70/*. The common size is 35/*. 



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

 and broad. Usually one or two of its lines are visible throughout their length and become somewhat 

 broader and hazy near the margin of the grain. They may be somewhat bent or otherwise distorted. 



The degree of polarization is high. It varies greatly in different grains, in different positions of 

 the same grain, and also sometimes in different parts of the same aspect of a grain. It is not so high as 

 that of the grains of C. warszewiczii. 



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

 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 and the color deepens quickly, some more than others. 

 The color is slightly deeper than that of the grains of C. warszewiczii. After heating the grains in 

 water until they are completely gelatinized, the solution colors fairly and the grains deeply on the 

 addition of iodine. After boihng for 2 minutes, the solution colors deeply and the grain-residues 

 lightly or not at all. The capsules color a red-violet with excess of iodine and many of them retain 

 blue-reacting starch at the proximal end. 



Staining Reactions. — With gentian violet and with safranin the grains begin to stain at once and 

 in 30 minutes are deeply stained, some more than others. The color is not quite so deep as that of 

 the grains of C. warszewiczii. 



Temperature Reaction. — The temperature of gelatinization is 68° to 70° C, mean 69°. 



Effects of Various Reagents. — With chloral hxjdrate-iodine reaction begins in a minute and is 

 over in 22 minutes. It is the same qualitatively as that of the grains of C. warszewiczii. 



Curve of Reaction-lntenaities of Starch of Canna var. 

 (L. E. Bally). 



