592 



STARCHES OF LILIACEiE, 



VL VL 80 



MINUTES 

 Curve of Reaction-Intensities of Starch of Brodisa i xoides 



72. 



CA PA FC P S CI PA CA 



Polariscopic Properties. The figure is eccentric, distinct, and usually clear-cut. Its lines tend 

 to be of the same distinctness throughout, but may be bent or otherwise distorted. They are placed 

 at varjing angles to one another. 



The degree of polarization is high. It varies greatly in different grains, being very high in some 

 and extremely low in others. It is low at the distal ends of many of the grains, and it varies accord- 

 ing to the aspect of the grain viewed. It is slightly lower than that of the grains of B. peduncularis. 



With selenite the quadrants are fairly well defined, unequal in size, and generally irregular in 

 shape. The colors in most cases are not piu-e. 



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

 some much more than others at first; with 0.125 per cent solution tiiey color lightly at first, but 

 the color deepens quickly, and some are more deeply col- 

 ored than others. They are as deeply colored as those Chart No. 

 of B. peduncularis. After heating until all are completely 

 gelatinized, the solution colors very lightly and the grains 

 very deeply with iodine. After boihng for 2 minutes the 

 solution colors more, but the grain-residues much less 

 deeply. The capsules are colored a red-violet with very 

 slight excess of iodine, and many still contain blue-react- 

 ing starch in the proximal end. 



Staining Reactions. With gentian violet and with saf- 

 ranin the grains begin to stain at once and in 30 minutes 

 are lightly stained, some more than others. The shade is 

 the same as that of B. peduncularis. 



Temperature Reaction. The temperature of gelatin- 

 ization is 61.5 to 62 C, mean 61.75. 



Effects of Various Reagents. With chloral hydrate- 

 iodine a few grains begin to react in 30 seconds. About 

 half are darkened in 5 minutes, three-fourths in 15 min- 

 utes, and five-sixths in 25 minutes. The reaction is quali- ^ar. .piende 

 tatively the same as that of the grains of B. peduncularis. 



With chromic acid some grains begin to react in 30 seconds and most of them in a minute. 

 The reaction is general in 2 minutes and over in 6 minutes, and is qualitatively the same as that 

 of the grains of B. peduncularis. 



Reaction with pyrogaUic acid begins in a few grains at once and is general in 2 minutes. All 

 the grains are completely gelatinized in 5 minutes. The reaction is qualitatively the same as that 

 of the grains of B. peduncidaris. 



Reaction with feiric chloride begins in a few grains at once and in about half in 1 J^ minutes. 

 About thi-ee-fourths are fully gelatinized in 10 minutes, all but a very few in 25 minutes, and practi- 

 cally all in 50 minutes. The reaction is qualitatively the same as that of the grains of B. peduncularis. 



With Purdy's solution some few grains begin to react at once and the reaction is slight but 

 general in IJ o minutes. Most of the small grains and a few of the medium-sized are nearly or com- 

 pletely gelatinized in 5 minutes. About half are partially or completely gelatinized in 15 minutes, 

 but the reaction is incomplete in an hour. The reaction is quahtatively the same as that of the 

 grains of B. peduncularis. 



STARCH OF BRODI^A CANDIDA. (Plate 45, figs. 269 and 270. Chart 173.) 



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

 pounds; the smaller show some tendency to form doublets and triplets; the larger sometimes have 

 several smaller grains adherent. The compound grains may be made up of two small grains sur- 

 rounded by several layers of starch. There is a marked tendency among the gi-ains to unite in 

 large clumps. The grains are often distorted by nodular, spicular, or rounded processes, and it 

 is not uncommon to see a perfectly formed primary grain, embedded or partially surrounded and 

 thus distorted by irregular masses of amorphous matter. The most conspicuous forms are the 

 long, pointed oval. There are broader and blunter, oval and ellipsoidal, and various modifications 

 of them. The grains are not flattened in any diameter, and when turned over have the same 

 dimensional characteristics as B. peduncularis. 



