404 STARCHES OF LEGUMINOS^. 



gradually assume a golden-brown color. The grains which become gelatinized are stained either 

 a light violet or light rose tint, and the lamellae become very distinct and have delicate stria?, espe- 

 cially in imfissured grains. In the forms with deep stellate clefts, this color is a golden-brown at 

 once, but later the blue color starts centrally and spreads throughout the grain, accompanied by 

 uniform swelling. Gelatinization usually starts at one end, or at the lines of separation of the aggre- 

 gates or part-grains, and advances slowly. The gelatinized grain, while much swollen, retains in 

 general the form of the untreated grain. There is a central light space from which light lines extend, 

 dividing the grain into segments which sometimes are practically separated from one another. 



The grains begin to react at once with chromic acid. The grains with stellate fissures are fre- 

 quently dissolved in 20 seconds, except a refractive mass of granules which do not pass into solution. 

 The grains, which resemble those of Lathyrus, are all dissolved in 3 minutes. The former swell 

 rapidlj', sometimes breaking into segments or part-grains during the reaction, and are dissolved, 

 except the mass of refractive substance referred to. In the few grains which resemble those of 

 Lathyrus the mesial fissure becomes very distinct; the lamellae are sharply differentiated into refrac- 

 tive and non-refractive lamellae, the refractive lamellae exhibiting striae; and delicate radiating 

 fissures pass from the central fissure to every part of the grain. The grain swells uniformly, becomes 

 very clear, and then suddenly collapses and passes into solution. 



Reaction with pyrogallic acid begins in some grains at once. A few are gelatinized in 2 minutes 

 and all are more or less affected in that time. There is very little further change even after an hour. 

 The lamellae become very distinct and exhibit striae. In the forms with stellate fissures bubbles 

 collect in the fissures and disappear as the grains swell. In some grains the starch immediately 

 surrounding the fissures becomes gelatinized, while most of the grain continues unaffected after the 

 first steps of the process. In other grains a clear spot appears at the apex of each part-grain of the 

 grain, and these part-grains occasionally separate and the parts swell independently. A number 

 of refractive granules are found along the course of the clefts in all swollen grains. The gelatinized 

 grain, though much enlarged, retains the general shape of the untreated grain. A few grains similar 

 to those observed in Lathyrus odorahis var. shahzada are completely gelatinized in 2 minutes. The 

 reaction and the shape of the gelatinized grain are the same as in L. odoratus var. shahzada. 



The grains begin to react in 30 seconds with ferric chloride, the lamellae becoming distinct. 

 In 15 minutes practically all are partially gelatinized, and the reaction is complete in a few in 20 

 minutes. Nearly all are gelatinized in 30 minutes, but after remaining in the reagent for an hour 

 there is little if any further change in the few remaining ungelatinized grains. The lamellae become 

 distinct, the stellate fissure swells and bubbles usually form in it. If the fissure is very deep, the 

 grain frequentlj' separates into segments. Some of the outer lamellae appear to break as the gelat- 

 inized starch expands. Some of the grains do not separate into parts, in which case the gelatinized 

 grain retains much of the shape of the untreated grain. 



With Purdy's solution the grains begin to react in 30 seconds. A few are gelatinized in 5 min- 

 utes, all of the grains are in process of reacting in 15 minutes, and the reaction is complete in 30 

 minutes. The phenomena of the reaction are similar to those noted for pyrogallic acid, but gelati- 

 nization proceeds somewhat further in the fissured forms. The few grains resembling those of 

 Lathyrus odoratus var. shahzada are completely gelatinized. The gelatinized grain still retains 

 much of the shape of the untreated grain, and parts of the outermost lamellae are ungelatinized. 



STARCH OF PISUM SATIVUM VAR. (EUGENIE, YELLOW). (Plate 8, figs. 47 and 48. Chart 46.) 



Histological Characteristics. — In form, as in the green Eugenie peas, these grains appear to be 

 simple. There are few aggregates. Most of the grains are partially divided, usually into four to 

 nine parts, commonly five or six, by very deep, wide, and somewhat irregular fissures. The grains 

 are of the round, ovoid, and oval type, but the marginal outline is so broken up, owing to the fissur- 

 ing of the grain, that they have a rosette-like appearance. Many part-grains also arise from the 

 breaking up of the primary grain, and these pieces are irregularly wedge-shaped, crcscentic, tri- 

 angular, or quadrangular. Grains of the type common to Vida and Phaseolus, which have but one 

 long fissure extending down the middle, are rarely to be found. 



No hilum is demonstrable. 



The lamdlcB are not demonstrable except by treatment, as with Purdy's solution. When the 

 grains are so treated the lamellae appear as rather coarse, regular lines, which are made discontinuous 

 by the fissuring. There are about 8 or 9 on the larger grains. 



>.. 



