GENUS CONVALLAKIA. 617 



With selenite the quadiants are well defined. In the smaller they are regular, but usually unequal 

 in size; in the larger they are often irregular in shape and unequal in size. The colors of the small 

 grains are dark, but appear to be pure, and in the larger bright but frequently impure. 



Iodine Reactions. With 0.25 per cent Lugol's solution the smaller grains color a fairly deep 

 blue-violet and the larger a red violet, the color in both deepening rather rapidly; with 0.125 

 per cent solution the small grains color a light blue-violet, the larger a light reddish-violet, the 

 color in both deepening rather rapidly to a fairly deep tint. After heating in water until the grains 

 are gelatinized, and then adding iodine, the solution colors a deep heliotrope and the grains a light 

 reddish-violet to deep heliotrope. If the grains are boiled for 2 minutes and then treated with iodine, 

 most of the small grain-residues are colored a violet to light red-violet, and some remain unstained, 

 and the large grain-residues become a deep heliotrope, while the solution becomes a deep reddish- 

 blue. With an excess of iodine the capsules of the smaller grains become a light reddish-violet to 

 deep old-rose, those of the large ones a deep old-rose to a wine-red. The grain-residues color a very 

 deep heliotrope. 



Staining Reactions. With gentian violet and with safranin a few grains color slightly at once 

 and in 30 minutes they are very lightly stained, some more than others. 



Temperature Reactions. The temperature of gelatinizatiou for the smaller grains is 60 to 

 62 C, mean 61., for the majority of larger ones 71 to 72.5., mean 71.75 C. Some of the large 

 and medium-sized grains remain unaffected at 77 to 79 C. 



Effects of Various Reagents. With chloral hydrate-iodine reaction begins at once. Many small 

 grains are gelatinized in 15 seconds and all in 30 seconds; while the larger are gelatinized in 5 minutes 

 and all in 15 minutes. The reaction is so rapid and the grains so small that the details frequently 

 can not be studied. The large grains are quickly stained an old-rose color and the structure at the 

 hilum swells and becomes sharply defined. The grains deepen in tint until they are a wine-red color, 

 the blue coloration starts at the distal end, spreads around the margin, and then advances over 

 the entire grain, accompanied with miiform swelling. The cleft or the cavity located at the hilum 

 gradually decreases until it is obliterated. The most resistant grains have either a very large cavity 

 or cleft at the hilum which swells and becomes of a metallic luster, persisting for many minutes, 

 while the grain remains a deep wine-red color for a similar period, but finally the cavity or cleft 

 disappears and the grain becomes deep blue in color. The gelatinized grains are much swollen, 

 but retain the shape of the untreated grain. 



Reaction with chromic acid begins immediately. The small gTains are dissolved in 20 seconds, 

 while the larger usually pass into solution in 23/^ minutes, but some resistant grains take 6 minutes 

 for solution. The reaction begins immediately and most of the grains are so small that the details 

 can not be studied with accuracy. In the large grains the cleft or the cavity at the hilum swells; 

 this is quickly followed by gelatinizatiou of the central part of the grain, accompanied by the appear- 

 ance of many refractive granules. The outer lamella become sharply defined and striated and the 

 entire grain increases much in size. The capsule is ruptured either at the distal end or at the 

 corners of this end. The gelatinized starch slowly flows from the capsule and is dissolved, followed 

 by solution of the rest of the capsule. 



The reaction with pyrogallic acid begins immediately. All the smaller grains are gelatinized 

 in 30 seconds, many of the larger ones in a minute, and all but rare resistant grains in 3 minutes, 

 the reaction being complete in the latter in 5 minutes. In the small grains the hilum swells and the 

 entire grain is gelatinized so rapidly that the details can not be noted. In the large grains the clefts 

 or the cavity at the hilum swells and branches of gelatinizatiou pass from them towards the sides 

 and distal end of the grain, and the lamellaj become more distinct and striated. Bubbles are given 

 off from the deep clefts or cavity and gelatinizatiou quickly follows. The reaction progTesses more 

 rapidly towards the sides and distal end of the grain, which parts are thrown into folds and distorted, 

 while at the same time the proximal end retains the contour of the untreated grain. 



Reaction with feme chloride begins immediately. Some of the small grains are gelatinized in 

 30 seconds, nearly all in a minute, and all but rare resistant grains in 2 minutes, the latter requiring 

 as long as 30 minutes. With the large ones the reaction begins in some in a minute and is complete 

 in a few in 3 minutes. About one-third are gelatinized in 5 minutes, three-fifths in 15 minutes, and 

 all but rare resistant grains in 30 to 60 minutes. In most of the small grains gelatinizatiou spreads 

 so rapidly over the entire grain that the details can not be satisfactorily made out. In the large 

 grains the clefts or the cavities at the hilum swell rapidly and a bubble of air appears in them; a 



