514 



STARCHES OF LILIACE^E. 



PC PS 

 6 



STARCH OF CALOCHORTUS BENTHAMI. (Plate 28, figs. 167 and 168. Chart 122.) 



Histological Characteristics. In form the grains are simple and isolated, with few exceptions. 

 There are no pressure facets. Many grains show amorphous additions which give a fan shape to 

 an otherwise ellipsoidal grain. These deposits at times assume the character of nipple-like processes. 

 In addition, some grains are irregular in outline, owing to the unequal development of the primary 

 grain. There is a decided tendency for the proximal end to be protruded in nodular form. The 

 conspicuous form is the eliip.soidal with blunt ends, both of which may be equal in size, or one may 

 be much broader tiian the other. There are also pyriform, ovoid, irregularly quadrangular, and 

 triangular grains. Most of the larger fan-shaped grains are formed by the addition of amorphous 

 masses to the distal end of the primary ellipsoidal grain. The grains are somewhat flattened, and 

 some are narrower at the proximal end than at the other. 



The hiluni is, as a rule, a distinct, medium-sized spot, situated eccentrically at about one-fifth 

 of the longitudinal axis and in the median line. It is never double or multiple. It occasionally is 

 marked by a clean-cut, transverse fissure. 



The latnellce are fairly distinct. They are rather fine, regular, continuous rings, which follow 

 closely the outline of the margin. Those immediately surrounding the hilum, and at times those 

 at the distal end, are the more distinct. They vary in size and distinctness in different grains. 

 There are about 16 to 20 lamellae on the larger grains. 



The grains vary in size from 4 to 40;^. The common 

 size is 32/i. 



Polariscopic Properties. The figure is eccentric, dis- 

 tinct, and clear-cut. Its lines are apt to become somewhat 

 broader but less distinct as they approach the margin. 

 They are also often bent and distorted and vary in width, 

 and may be placed at varying angles to one another. 



The degTee of polarization is high, higher than that 

 of the grains of C. nitidus. It varies somewhat, being 

 very low in certain parts of the grains, especially at times 

 near the margin. It varies also according to the portion 

 of the grain. 



With selenite the quacb-ants are clear-cut, very irreg- 

 ular in shape, and unequal in size. The colors ai'e pure. 



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

 tion the grains are colored a very deep blue-violet; with 

 0.125 per cent solution the grains color well at once and 

 the color deepens quickly. This color is deeper than that 

 of the grains of C. nitidus. After heating until all the 



grains are completely gelatinized, the solution is colored lightly and the grains very deeply on the 

 addition of iodine. After boiling for 2 minutes the solution is colored much more deeply, but the 

 grain-residues much less. Many of the capsules do not contain any blue-reacting starch. All the 

 capsules color violet when an excess of iodine is added. 



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

 and after 30 minutes they are deeply colored, some more than others. The color is deeper than that 

 of the grains of C. nitidus. 



Temperature Reaction. The temperature of gelatinization is 61 to 62 C. mean 61.5. 



Effects of Various Reagents. With chloral hydrate-iodine the reaction begins in 30 seconds 

 and is over in 5 minutes. It is qualitatively the same as that of the grains of C. nitidus. 



The reaction with chromic acid begins immediately and is over in 2 minutes. It is the same as 

 that of the grains of C. nitidus. 



With pyrogallic acid the reaction begins in 30 seconds and is over in 4 minutes. The reaction 

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



With ferric chloride the reaction begins in 15 seconds and is over in 5 minutes. It is qualita- 

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



With Purdy's solution the reaction begins in 10 seconds and is over in 30 seconds. It is quali- 

 tatively the same as the corresponding reaction in the grains of C. nitidus. 



Curve of Reaction-Intensities of Starch of 

 Calochortus benthami. 



