530 



STARCHES OF LTLTACE^. 



Polariscopic Properties. The figure is eccentric, except in some of the very small grains. Its 

 lines are thick and generally straight and expanded at the distal and proximal ends. Occasionally 

 they may be bent and rarely are bisected. The figure is the same as that of T. hagcri. 



The degree of polarization is fairly high. There is considerable variation in the different grains 

 and even in the same aspect of a given grain. It is not so high as in T. hageri. 



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

 The blue is quite pure, but the yellow is not pure, as in T. hageri. 



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

 with 0.125 per cent solution they color fairly and the color deepens rapidly. It is not quite so deep 

 as that of the grains of T. hageri. After heating in water until all the grains are completely gelatin- 

 ized, the solution colors fairly deeply and the swollen grains deeply on the addition of iodine. After 

 boiling for 2 minutes the solution colors very deeply, but the grain-residues lightly or not at all. 

 With a slight excess of iodine all the capsules color a red-violet. 



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

 stained, some slightly more than others. The stain is slightly deeper than that of the grains of T. hageri. 



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

 one as much as another. The color is deeper than that of the grains of T. hageri. 



Temperature Reaction. The temperature of gelatinization is 50 to 51.5 C, mean 50.75. 



Effects of Various Reagents. With chloral hydrate-iodine reaction begins in most grains in 

 30 seconds. It is over in most of them in 10 minutes and in all in 17 minutes. It is the same quali- 

 tatively as that of the grains of T. hageri. 



Reaction with chromic acid begins at once and is over in 45 seconds. It is the same qualitatively 

 as that of the grains of T. hageri. 



With pyrogallic acid reaction begins in a few seconds and is over in a minute. It is the same 

 qualitatively as that of the grains of T. hageri. 



Reaction with ferric chloride begins in a few grains in 15 seconds. It is over in nearly all in 6 

 minutes and in all in 10 minutes. It is the same qualitatively as that of the grains of T. hagcri. 



Reaction with Purdy's solution begins at once and is over in 45 seconds. It is the same quali- 

 tatively as that of the grains of T. hageri. 



Chart No. 



GV S T CI 



34. 



CA PA FC 



PS CI PA CA 

 ~ PC PS 



STARCH OF TULIPA DIDIERI VAR. MAURIANA. (Plate 32, figs. 191 and 192. Chart 134.) 



Histological Characteristics. In form the grains are simple and, almost without exception, 

 isolated. There are no pressure facets. The surface is usually somewhat irregular, owing to an 

 undulating margin and occasionally to nipple-like pro- 

 cesses near the hilum. The conspicuous forms among 

 the large grains are irregular ovoid, pyriform, flattened 

 eUipsoidal, oval, and clam-shell-shaped. The smallest 

 forms are oval, ovoid, ellipsoidal, and round. The grains 

 are flattened, and when viewed on edge they are fre- 

 quently seen to be narrower at the distal end. They are 

 the most irregular of all the tulip starches. 



The hilum is a round refractive spot, with a range of 

 eccentricity of one-fifth to one-seventh, usually one-sixth, 

 of the longitudinal diameter. A small transverse fissure 

 is sometimes present at the hilum. 



The lamellcB are usually fine and indistinct near the 

 hilum, and there is often one coarse, refractive lamella at 

 about three-fourths of the distance between the hilum and 

 the distal end. The lamellae are distinct and coarser in the 

 quarter-section near the distal end than between the refrac- 

 tive lamella referred to and the hilum. Often there ai-e two 

 of these coarse, refractive lamella), one at about one-fourth 

 and the other at three-fourths of the distance between tlie 

 hilum and the distal margin. There is an alternation of coarse lamellae with groups of fine lamella; 

 in the broadlj^ triangular and also in the somewhat clam-shell-shajjed grains. The lamellte are not 

 demonstrable throughout the entire grain, but occasionally 25 to 30 can be counted on a grain. 



Cur' 



MINUTES 



of Reaction-Intensities of Starch of Tulipa 

 didieri var. mauriana. 



