GENUS CHIONODOXA. 



549 



irregular rounded protuberances and nipple-like processes. The conspicuous forms are ovoid, oval, 

 elliptical, and bean-shaped or reniform. There are also clam-shell and mussel-shell types, pyriform, 

 ellipsoidal, lenticular, and various irregular forms. The grains when seen on edge appear somewhat 

 flattened, and are narrower at the distal than the proximal end. 



The hilum is very distinct, comparatively small, and eccentric from one-sixth to one-third of 

 the longitudinal axis of the grain. It is usually situated on a small rounded, ovoid, or reniform area 

 which is raised above the level of the rest of the grain. There may be 2 or more hila, and they are 

 generally grouped irregularly. Usually the hilum is not fissured, but when it is the fissuration may 

 be in the form of a small, transverse or longitudinal line, or 2- or 3-armed cross, or clean-cut or ragged, 

 or divided by small secondary fissures. 



The lamellce are not very distinct, rather coarse, continuous rings, irregular or regular according 

 to the outline of the margin. There are two sets, those located on the raised portion about the 

 hilum and those outside of this area, those near the hilum being the more distinct. The lamella 

 outlining the raised space is very prominent. There are 

 about 6 to 7 on a grain of medium size. 



The grains vary in size from 6 to 40ai. The common 

 size is 22/i. 



Polariscopic Properties. — The figure is distinct, and 

 usually eccentric, and clear-cut. It is much more sharply 

 defined than that in C. lucilice, and the lines are less apt 

 to be bent and otherwise distorted. The lines tend to 

 become much broader and less well defined towards the 

 margin, and they may vary much in width. 



The degree of polarization is fairly high. It is about the 

 same as in the grains of C. lucilice. There is not much var- 

 iation in the same and in different aspects of a given grain. 



With selenite the quadrants are well defined, irregular 

 in shape, and unequal in size. The colors are fairly pure. 



Iodine Reaction. — With 0.25 per cent Lugol's solu- 

 tion the grains color deeply a blue-violet; with 0.125 per 

 cent solution they are colored quite deeply and about the 

 same in both cases as the grains of C. lucilice. After heat- 

 ing until all the grains are fully gelatinized, the solution is 

 colored lightly and the grains very deeply on the addition of iodine. After boiling 2 minutes the 

 solution is much more deeply colored, but the grain-residues much less or not at all. With excess 

 of iodine all the capsules take on a violet color. The capsules still retain blue-reacting starch in the 

 proximal end. 



Staining Reactions. — With gentian violet and with safranin the grains begin to stain in 30 seconds, 

 and after 30 minutes are fairly well stained. The color is less than that of the grains of C. lucilice. 



Temperature Reaction. — The temperature of gelatinization is 60.2° to 62° C, mean 61.1°. 



Effects of Various Reagents. — With chloral hydrate-iodine reaction begins in 20 seconds. In 4 

 minutes most and in 12 minutes all of the grains are gelatinized. The reaction is the same quali- 

 tatively as that of the grains of C. lucilice. 



Reaction with chromic add begins at once. It is over in 2 minutes, except in some of the smaller 

 grains, which do not dissolve within 6 to 7 minutes. The reaction is the same as that of the grains 

 of C. lucilice. 



Reaction with pyrogallic add begins in 20 seconds. All are affected and most of the grains are 

 fully gelatinized in 3 minutes. The reaction is the same as that of the grains of C. lucilice. 



The reaction with ferric chloride begins in 20 seconds and is over in 8 minutes. It is the same 

 as that of the grains of C. ludlice. 



With Purdy's solution the reaction begins at once. Most grains are gelatinized in a minute. A very 

 few are refractory, and cease reacting after being partly gelatinized. There is apparently no further 

 change during an hour. The reaction is the same qualitatively as that of the grains of C. Iv/Mice. 



