GENUS TRIANOSPERMA. 891 



With selenite the quadrants are well defined, usually unequal in size, antl irregular in shape. 

 The colors are fairl.y pure. 



Iodine Rraclions. With 0.25 jicr cent Lugol's solution the grains are colored very deeply 

 blue-violet; with 0.125 per cent solution they color deeply. After heating in water until all the 

 grains are completely gelatinized, the solution and some of the grains are colored deeply on the 

 addition of iodine. After boiling for 2 minutes, the solution is colored very deeply, but the grain- 

 residues nuich less deeply or not at all. When an excess of iodine is a<l(lcd all the caiisules are colored 

 a dark violet. 



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

 in 30 minutes they are fairly deeply stained, some more than others. 



Tempa-ature Reaction. The temperature of gelatinization is 58 to G0 C, mean 59. 



Effects of Various Reagents. With chloral hydrate-iodine reaction begins at once and is over 

 in 5 minutes. Both hilum and lamellae become very prominent. A dark Imbble appears at the hilum. 

 The distal end of the grain begins to darken, especially about the edges of the facets, antl there is 

 often much swelling at these points. The whole margin darkens and the process spreads inward. 

 Meanwhile the dark bubble at the hilum swells, the hilum swells, and the bubble first increases 

 and then decreases in size. The hilum continues to swell with other parts of the grain until a gel- 

 atinous mass is formed. The gelatinized grains are large, but not very much distorted, and the 

 edges of the facets are somewhat puffed out. In some cases there appeared to be two parts to the 

 margin, a thick, dark inner ring, and a thin, light outer envelope. 



The reaction with chromic acid begins immediately and is over in IJ'^ minutes. The hilum is 

 frequently marked by a bubble. The lamellis become distinct. The hilum swells somewhat and 

 fine radial strite appear running throughout the grain. The bubble begins to swell, accompanied 

 by sweUing of the hilum and other parts of the grain, and shrinks after reaching a certain size. 

 The hilum and the grain, as a whole, swell with increasing rapidity as gelatinization proceeds. 

 The more resistant part of the grain at the margin forms, at first, a thick, homogeneous band, 

 which rapidly becomes thinner and transparent and finall}^ invaginated at one side. One point 

 dissolves, the contents are exuded and dissolved, followed by solution of other parts of the capsule. 



Reaction with pyrogallic acid begins in 20 seconds and is over in 2 minutes. Both hilum and 

 lamellae become very prominent. The hilum swells slightly and the grain becomes divided by fine, 

 radiating striae. The starch at the margin forms a thick, radially striated band, which becomes 

 thin and clearer. As the grain continues to swell invagination occurs, often very deeply in one side. 

 The edges of the facets are swollen out, frill-like, about the facets. The gelatinized grains are large 

 and occasionally somewhat distorted, especially when invaginated, but generally they are smooth 

 and not wrinkled, except about the edges of the facets. 



With ferric chloride the reaction begins in 30 seconds and is over in 5 minutes. The hilum be- 

 comes very pronoinent as a dark bubble, which frequentlj' does not appear until other parts of the 

 grain begin to react. As this bubble enlarges, the inner part of the grain is gelatinized and the 

 grain swells. The bubble at the hilum, having reached its limit of expansion, begins to shrink 

 and finally disappears. The grain continues to swell, but even more rapidly. The starch at the 

 margin forms a thick, homogeneous ring, which becomes thinner, and finallj^ in many grains 

 invaginates, usually deeply, at some point. The gelatinized grains are very large, some are deeply 

 invaginated, and the edges of the facets are filled. 



The reaction with Purdy's solution begins in 30 seconds and is over in 3 to 5 minutes, but none 

 of the grains is fully gelatinized. Both hilum and lamella; become very prominent. The grain 

 becomes divided by fine striae, and the inner portion is transformed into a gelatinous mass, while 

 the outer portion forms a striated, banded ring, which at first is very thick, but later somewhat 

 thin, homogeneous, and transparent. 



