394 STARCHES OF LEGUMINOS^. 



and the graiii-rrsidncs a less deep blue. When an excess of iodine is atltled the capsules color a 

 red-violet to red-purple. 



Stainivg Reactions. With gentian violet a few {grains color slightly immcxliatcly and in 30 

 minutes some of them are stained a light violet. The grains in which the mesial cleft is not deep 

 or is absent are more quickly stained. 



With safranin a few grains color slightly at once and in 30 minutes they are all lightly stained. 



Temperature Reaction. The temperature of gelatinization is 71.5 to 73 C, mean 72.25. 



Effects of Various Reagents. With chloral hydrate-iodine the reaction begins in a few grains 

 in a minute and gelatinization is complete in a small number in 5 minutes. About one-fifth are 

 gelatinized in 10 minutes, about two-fifths in 30 minutes, and about two-thirds in an hour. The 

 lamella? become sharply defined, but the mesial cleft is not so well marked, although a thorn-like 

 transparent structure is sometimes formed in the mesial, non-lamellated portion of the grain. 



Occasionally either a dark ring or slit-like formation appears in the central part of the grain, 

 which becomes irregular in outline and is finally obscured as gelatinization and the accompanying 

 deep-blue coloration advance towards this region. Gelatinization usually begins at one end and pro- 

 ceeds gradually over the grain, accompanied by uniform swelling. The gelatinized starch colors a 

 deep l^lue and the rest of the grain an old-rose. In reniform grains and indented forms, gelatiniza- 

 tion may start at the depression or indentation and be followed by another focus of reaction at a 

 point on the opposite side. The grains which are not completely gelatinized become granular in 

 appearance and of an old-rose to a light reddish-brown tint, with a lighter central area and sur- 

 rounded by a clearer border. The gelatinized grains are much swollen, but retain the general shape 

 of the untreated grain. They are deep blue in color and frequently with clear lines which are 

 located at the region of the clefts in the untreated grain. 



The reaction with chromic acid begins in 20 seconds. A few grains arc dissolved in a minute, 

 the majority in 3 minutes, about six-sevenths in 5 minutes, and practically all in 13 minutes. The 

 refractive and non-refractive lamella; become very sharply defined, and fine stria; appear in the 

 former. The clefts, or hilum if demonstrable, become very distinct, liut if a cleft is not present a 

 thorn-like fissure is quickly formed in the mesial non-lamcUated portion of the grain. Gelatiniza- 

 tion proceeds along the course of the branched fissures and the grain swells uniformly, assuming 

 an oval shape. During the solution of the lamellfe, irregularly distributed, refractive bodies appear 

 which remain for some time embedded in the dissolved starch. These grains become clearer until 

 finally the entire mass is in solution. In the very resistant grains, as the refractive bodies pass into 

 solution, the capsule becomes distorted and rujitures simultaneously at two or more points. 



Reaction with pyrogallic acid begins in a few grains in 30 seconds and jiractically all are in 

 various stages of dissolution in Ij^ minutes. The reaction is complete in a few in a minute, in nearly 

 all in 23^ minutes, and in practically all in 5 minutes. The clefts, hilum, and lamcike become very 

 distinct. If clefts were not present at the position of the hilum, they are quickly formed, and deli- 

 cate branches pass from them to all parts of the grains. The lamelhe become striated, and as they 

 are gelatinized, refractive bodies appear which remain embedded in the altered starch. In many 

 of the gelatinized grains the structure of the lamelhe can be detected, the lamella? being thrown into 

 folds and held in place by refractive bodies. A deep, elongated cleft frequently passes through 

 the center of the gelatinized grains, completely dividing the grains at one or both ends. A small 

 number of the grains are completely gelatinized, except a few refractive bodies embedded in the 

 gelatinized starch. The gelatinized grains are so swollen and distorted that they do not resemble 

 the shape of the imtreated grain. 



With ferric chloride swelling liegins in a few grains in 2 minutes. It is complete in a very small 

 number in 18 minutes, in about one twenty-fifth in 30 minutes, and one-tenth in an hour. A luir- 

 row, transparent border is formed around the grain and the lamella; become striated and sharjily 

 defined. Gelatinization accompanied by distension of the capsule usually begins at one point and 

 may proceed gradually over the entire grain, or swelling may also appear at the opposite end of the 

 grain. The central part of the grain is the last to undergo gelatinization. In some grains the trans- 

 parent, narrow border becomes broader and irregular in outline, followed by simultaneous gela- 

 tinization at several points. In the reniform grains the swelling frequently begins at the depression 

 at one side of the grain. During the reaction small particles of ungelatinized starch may from time 

 to time be broken from the main mass and be gelatinized separately, this breaking up going on 

 until near the completion of the process, when the more resistant starch is forcibly divided into 



