GENUS RICHARDIA. 453 



of iodine the solution is colored very deeply, the grain-residues and the fragments very slightly 

 or not at all. When a slight excess of iodine is added, the capsules are colored a pinkish-violet. 

 Occasionally some blue-reacting starch is contained in the capsule. 



Staining Reactions. — With gentian violet the grains begin to stain immediately, but very slightly, 

 and after 30 minutes the stain is light. All the grains are stained equally. The color is about the 

 same as that in R. elliotiana. 



With safranin the grains begin to stain very slightly within a minute. After 30 minutes they 

 are very slightly stained, and less than R. elliotiana.. 



Temperature Reaction.- — The temperature of gelatinization is 77° to 78° C, mean 77.5°. 



Effects of Various Reagents. — With chloral hydrate-iodine the reaction begins in 30 seconds in 

 some grains and is over in all in 10 minutes. The hilum becomes prominent as a dark spot. The 

 lamellae are invisible. The grains are at first colored a light violet. One of the corners formed 

 by facets now darkens and some irregular protrusion takes place here. This process spreads grad- 

 ually over the whole grain, first involving the side on which it began, and from here spreading 

 around the margin, the central portion being the last to be involved. Some smaller grains darken 

 very rapidly all over and then swell. The gelatinized grains are not very large, and somewhat dis- 

 torted in shape, the part first affected being more swollen than the rest; all show a dark, homogeneous, 

 marginal ring inclosing a lighter, more or less circular area which represents the swollen hilum. 



Reaction with chromic acid begins in 2 minutes and is complete in 10 minutes. The hilum and 

 lamelhe become extremely prominent. Fine cracks or striae appear radiating from the hilum. 

 These grow more and more prominent and the hilum swells, or rather opens out, owing to an enlarge- 

 ment of some of the fissures previously formed. The immediate general result is a swollen grain 

 consisting of an ungelatinized substance in the form of a peripheral ring that is divided into distinct 

 parts and surrounds a mass of gelatinized starch. The outer portion of this ring is radially striated, 

 but otherwise homogeneous in appearance; the inner portion, which is often separated from the 

 outer by a very distinct clear space, consists of a row of coarse granules separated from one another 

 by the lines of cleavage already noted. The grain continues to swell, the marginal ring becomes 

 thinner and clearer until one part dissolves, the inner, faintly granular portion flows out and is 

 dissolved, followed by solution of the rest of the ring or capsule. 



With pyrogallic add the reaction begins in 8 minutes, very few grains being affected. (Out- 

 side of the cover-slip all the grains were completely gelatinized in 20 minutes.) The hilum becomes 

 distinct and the lamellte are fairly prominent. The grain becomes divided by fine striae which radiate 

 from the hilum, the hilum swells, and the ungelatinized portions of the grain are moved peripher- 

 ally to form a marginal ring consisting of two parts, an outer striated band marked by faint, alter- 

 nate refractive and non-refractive rings, and an inner granular band. The outer band grows thinner 

 and fainter as the grain continues to swell, and the inner band becomes mingled with the gelatinized 

 starch within. The gelatinized grains so formed are fairly large in comparison with the original 

 grains, and are not distorted, folded, or crumpled. 



The reaction with /emc chloride begins in some grains in a minute and in all in 2 minutes. It is 

 completed in 134 hours. The hilum is prominent as a dark spot; the lamellae are invisible. Some 

 grains react very rapidly. The hilum, and also the gi-ain as a whole, undergoes swelling. Any inter- 

 mediate stages are passed through so rapidly that they are not determinable. The result is a gelat- 

 inized grain having a thin, homogeneous capsule which is not folded or distorted. Other grains 

 react slowly, first showing fine, radiating striae, and then, as the hilum swells and the ungelatinized 

 portions are pushed out to the margin, two layers are formed, as in the reactions to chromic acid 

 and pyrogallic acid, but often not so plainly marked. The marginal ring becomes thinner, clearer, 

 and quite homogeneous as the grain continues to swell. The gelatinized grains are large and rounded, 

 not much folded, crumpled, or otherwise distorted. 



The reaction with Purdy's solution begins in about 5 minutes in a very few grains. After l}/^ 

 hours only a very few grains are completely gelatinized; other grains are entirely unaffected. The 

 hilum and lamellae do not become especially prominent. The grains first show fine striae radiating 

 from the hilum; then the hilum swells and the ungelatinized portions of the grain push out to the 

 margin, where they form a marginal ring of two parts, not very definitely separated — an inner 

 row of large granules, and an outer, more or less homogeneous layer having fine striae. These layers 

 gradually become clearer and thinner as the grain swells, forming a capsule. The gelatinized 

 grains are fairly large and not folded, crumpled, or otherwise much distorted. 



