GENUS OALOCHOnTtJS. 



513 



STARCH OF CALOCHORTUS MAWEANUS VAR. MAJOR. (Plate 28, figs. 105 and 100. Chart 121.) 



Histological CharaderiHlics. — In form the grains are simple and usually isolated. There arc no 

 pressure facets. The surface is often somewhat irregular, owing to irregularities in the development 

 and to amorphous additions to the primary part of the grain. The conspicuous form is elliptical, 

 which is commonly quite regular. There are many round or almost round, fan-shaped, irregularly 

 polygonal with rounded corners, very broad pyriform, and triangular with a rounded base. The 

 grains are somewhat flattened, and some are narrower at one end than at the other. 



The hilu7n is not very distinct and often shows two lines or fissures extending from it on each 

 side. It is a small round spot, eccentric to about one-fifth of the longitudinal axis of the grain, located 

 towards the smaller end, and usually in or near the median line. There are no double hila. If the 

 hilima is fissured, the fissure is very small and does not communicate with the interior. 



The lamella are not very distinct and are rather fine. They are often irregular owing to the 

 unevenness in the surface of the grains. They appear to be arranged so that large, rather coarse 

 lamellae alternate with bands of others finer and less dis- 

 tinct. They are not so fine near the distal end and vary 

 in size and distinctness in the different grains. There are 

 20 to 24 on the larger grains. 



The grains vary in size from 4 to 46/u. The common 

 size is 30ju. The common size of the elliptical grains is 

 32 by 2^ix in length and width, and of the fan-shaped 

 grains 30 by 2&ix in length and width. 



Polariscopic Prope)-ties.— The figure is eccentric, dis- 

 tinct, and frequently clear-cut. Sometimes the lines are 

 broader and less well defined, especially near the margin. 

 They may be bent and distorted, and may be placed at 

 varying angles to one another. 



The degree of polarization is high, varying in dif- 

 ferent grains and in different positions of the same grain. 

 It is somewhat higher than in the grains of C. nitidus. 



With sele7iite the quadrants are usually well defined, 

 are unequal in size, and often very irregular in shape. 

 The colors are fairly pure. 



Iodine. Reactions. — With 0.25 per cent Lugol's solu- 

 tion the grains color very deeply, some more than others; with 0.125 per cent solution they color 

 lightly and the color deepens rapidly. The shade is lighter than that of the grains of C. nitidus. 

 The color is blue-violet. After heating until the grains are completely gelatinous the solution colors 

 lightly and the grains fairly deeply on the addition of iodine. After boiling for 2 minutes the 

 solution colors much more deeply and the grain-residues much less. The capsules all color red- 

 violet with a slight excess of iodine. 



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

 in 30 minutes are fairly well stained. The shade is about the same as that of the grains of C. nitidus. 



Temperature Reaction. — The temperature of gelatinization is 59° to 00° C, mean 59.5°. 



Effects of Vario^is Reagents. — With chloral hydrate-iodine some of the smaller grains begin to 

 react in 30 seconds and are gelatinized in 13^ minutes. All the grains begin to react in 45 to 60 

 seconds, about half are gelatinized in 4 minutes, and all in 10 minutes. The reaction is qualita- 

 tively the same as that of the grains of C. nitidus. 



Reaction with chromic acid begins immediately and is over in a minute. It is qualitatively 

 the same as that of the grains of C. nitidus. 



The reaction with pyrogallic acid begins in some grains at once and is general in 20 seconds. 

 It is over in 8 minutes, but a very few of the grains are not completely gelatinized at this time. 

 The reaction is qualitatively the same as that of the grains of C. nitidus. 



With ferric chloride some of the smaller giains begin to react in a minute and there is a general 

 reaction in 2 minutes. About half are completely gelatinized in 4 minutes and all in 8 minutes. 

 The reaction is qualitatively the same as that of the grains of C. nitidus. 



The reaction with Purdy's solution begins at once and is over in 30 seconds. The reaction is 

 qualitatively the same as that of the grains of C. nitidus. 



Curve of Reaction-Intensities of Starch of Calochortua 

 maweanus var. major. 



