GENUS TRITONIA (MONTBRETIA) . 



731 



P I GV T P 

 S 



Chart No. 282. 



GV S T CI CA PA FC P S CI PA CA 

 ~ . pj,p5 



S I 



The hilu7n is a rather large, fairly distinct round spot, and may be double or triple in a simple 

 grain. With doublets and triplets 2 or 3 hila may be seen. The single are centric or only sHghtly 

 eccentric. If there are 2 or more each may have its own set of lamelliD, which in some cases becomes 

 fused; or the hila may be close together in a clear, homogeneous, non-lamellated space and surrounded 

 by rather coarse, distinct lamellje. Fissuration was not observed. 



The lamelloe are rather indistinct. If Purdy's solution be used they become quite apparent 

 as rather coarse, regular, continuous rings of equal coarseness and equal distinctness. There are 

 about 4 or 5 on one grain, and usually 2 or 3 about each hilum if there are more than one hilum 

 and each hilum has a separate set of lamellae. 



The giains vary in size from 2 to 30/i. The common size is 18^. 



Polariscopic Properties. The figure is eccentric to slightly eccentric, but as a rule clear-cut. 

 The lines become broader, but not sharply defined, as they extend to the margin of the grain. There 

 are double or triple figures caused by the presence of two 

 or more component grains. 



The degree of polarization is fairly high. It varies 

 somewhat in different grains, but not much in different 

 aspects of the same grain. It is distinctly higher than 

 in T. crocata. 



With selenile the quadrants are not as a rule well 

 defined; they tend to be regular in shape but often un- 

 equal in size. If there are two or more hila an indistinct 

 mass of lines and colors appears in the center of the grain, 

 outside of which are the regular large quadrants. The 

 colors are fairly pure. 



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

 tion the grains are colored fairly, not so deeply as those 

 of T. crocata; with 0.125 per cent solution they are colored 

 lightly and the color is blue-violet. After heating until 

 the grains are completely gelatinized, the solution is col- 

 ored very lightly and the grains very deeply when iodine 

 is added. After boiling for 2 minutes the solution will 

 color more deeply, but the grain-residues less deeply. 

 Some of the grains exhibit a violet-colored capsule, but generally this color is obscured by a large 

 amount of blue-reacting starch remaining within the capsule. 



Staining Reactions. With gentian violet the grains stain very lightly at once and after 30 minutes 

 they are still very Ughtly colored, lighter than that of T. crocata. 



With safranin the grains begin to stain immediately very lightly and after 30 minutes they are 

 still very hghtly colored. The stain is much lighter than that of T. crocata. 



Temperature Reaction. The temperature of gelatinization is 80 to 82 C, mean 81. 



Effects of Various Reagents. With chloral hydrate-iodine some injured grains begin to react 

 immediately and some smaller grains in a minute. The reaction is practically general in 2 minutes. 

 All the small grains and about one-fourth of the large ones are dark in 7 minutes, about four-fifths 

 in 17 minutes, and all in 30 minutes. The hila are usually distinct, but the lamellae are obscured. 

 The grains become very dark around the entire margin and the coloration spreads inward evenly 

 over the whole grain. There is no sharp line of demarcation between the affected and unaffected 

 parts of the grain, and not much sweihng until the whole grain is dark. The gelatinized grains so 

 formed are not very large, have a dark-blue color, and retain much of the original form. 



The reaction with chromic acid begins in some grains in 30 seconds, it is general in a minute, 

 and over in 18 minutes. The hilum is very distinct, but the lamella) are not. The hilum swells 

 somewhat and fine stria; appear, radiating from it throughout the grain. These stria; widen as 

 the hilum continues to swell. The inner portion of the grain gradually becomes gelatinous. The 

 more resistant starch at the margin forms a thick ring which gradually becomes thinner. Later 

 the ring is divided into two distinct parts, the outer portion becomes very thin, transparent, wrinkled, 

 and folded, while the inner portion remains thick and retains a rounded form. The upper part of 

 the outer layer dissolves and the inner layer with its contained gelatinous material is extruded 

 partly or completely. Usually, however, before the two portions are completely separated the top 





Curve of Reaction-Intensities of Starch of Tritoma 

 securigera. 



