GENUS GLOXINIA (sINNINGIA). 889 



deepens rapidly. After heating in water until all the grains are completely gelatinized and then 

 adding iodine, the solution colors a bright indigo-blue and the gelatinized grains a deep blue. If 

 the grains are boiled for 2 minutes and then treated with iodine, the solution colors a very deep 

 indigo-blue, but most of the grain-residues remain colorless. With an excess of iodine the grain- 

 residues color a deep blue, some with reddish tint, and the capsules color a wine-red. 



Stai7ii72^ Reactions. With gentian violet and with safranin the grains begin to color immediately 

 and in 30 minutes are lightly to fairly colored. 



Temperature Reaction. The temperature of gelatmization is 68.5 to 70 C, mean 69.25. 

 At this temperature there are several grains which show no apparent effect of the heat. 



Effects of Various Reagents. With chloral hydrate-iodine reaction begins immediately. A few 

 grains are gelatinized in 30 seconds, and practically all in a minute. In the rare resistant grains 

 the reaction is complete in 2 minutes. The grains color a deep old-rose immediately and a dark 

 dot or line frequently appears at the hilum. Gelatinization begins either by the darkening of the 

 distal end or in the secondary sets of lamellEe or protuberances on the grain, and gradually spreads 

 all over the grain, accompanied by uniform swelling. The gelatinized grains are swollen, but retain 

 the shape of the untreated grain. 



The reaction with chromic add begins immediately. A few grains are dissolved in 15 seconds, 

 nearly all in 30 seconds, and all in 40 seconds. The hilum swells and a large bubble frequently 

 appears at this point, which as it collapses is often accompanied by an invagination of the proximal 

 end. Gelatinization quickly follows, and one or two large, internal, branched fissures pass from 

 this gelatinized area towards the distal end. The outer lamella become sharply defined and stri- 

 ated, and when disorganized at the distal end a cluster of refractive granules may remain for a few 

 seconds embedded in the more soluble starch. The grain continues to swell and the capsule is 

 ruptured at the proximal end, followed quickly by a complete solution of the outpouring starch 

 and later of the capsule. 



The reaction with pyrogallic acid begins immediately. A few grains are gelatinized in 15 seconds 

 and all but rare resistant grains in 30 seconds. All are usually gelatinized in a minute, but rarely 

 the reaction takes 3 minutes. A bubble appears at the hilum, which increases in size and then is 

 expelled, frequently accompanied by an invagination of the proximal end. In the narrower grains 

 from two to five internal longitudinal fissures, and in the broader grains a cluster of fissures, pass 

 from around the hilum to the distal end and gelatinization of the entire grain with the occasional 

 exception of a few refractive granules quickly follows. The gelatinized grains are much swollen 

 and are more distorted at the distal end. 



Reaction with ferric chloride begins in a few grains in 30 seconds. A small number are gelatinized 

 in a minute, about two-thirds in 5 minutes, nearly all in 7 minutes, and all in 10 minutes. The hilum 

 becomes distinct and sometimes a bubble appears which enlarges and collapses, the latter being 

 accompanied by a breaking up of resistant starch into large refractive granules, which are finally 

 dissolved. A lustrous border forms around the grain. Gelatinization accompanied by a rapid 

 distension of the capsule usually begins at the distal end and advances towards the proximal end. 

 In the less resistant grains the bubble at the hilum breaks, followed by similar gelatinization at 

 the proximal end. In the most resistant grains the bubble continues to enlarge and persists until 

 gelatinization has moved from the distal end and has about reached it, when it is expelled, the 

 resistant starch breaking up into large granules which usually become completely gelatmized. 

 Occasionally a few small, refractive granules remain. The gelatinized grain is much swollen and 

 distorted and does not resemble the form of the untreated grain. 



Reaction with Purdj/'s solution begins immediately. Many grains are gelatinized in 15 seconds, 

 about three-fifths in 30 seconds, nearly all in 2 minutes, and all but very rare resistant grains and the 

 distal parts of a few resistant grains in 4 minutes. The reaction is usually completed in the distal 

 end in 6 minutes; but in the rare resistant grains (one m many hundred) the reaction may take an 

 hour for completion. The hilum swells, a large bubble appears at this point, and the lamellaj 

 become very distinct and striated. The bubble collapses, frequently accompanied by an invagination 

 of the proximal end, and gelatinization of the starch m this region qiiickly follows. During this rapid 

 gelatmization there is often a decided lateral expansion of the grain at this point. From the gelat- 

 inized area of the narrower grains two to five internal parallel longitudinal fissures, and from the 

 broader grains a cluster of fissures, pass to the distal end, the starch of which latter is much more 

 resistant than that of the proximal end. The lamella; are finally gelatinized, except occasionally a 



