496 



DATA OF PROPERTIES OF STARCHES OF PARENT- AND HYBRID-STOCKS. 



the grains and 93 per cent of the total starch in 15 

 minutes ; in about 76 per cent of the grains aud 95 per 

 cent of the total starch in 30 minutes; in about the 

 same percentage of the grains and in more than 99 per 

 cent of the total starch in 45 minutes ; little if any further 

 advance in 60 minutes. (Chart D 216.) A small area 

 of the margin in a number of grains is very resistant. 



The reaction with potassium hydroxide begins imme- 

 diately. Complete gelatinization occurs in about 86 per 

 cent of the entire number of grains and 95 per cent of the 

 total starch in 3 minutes; in about 90 per cent of the 

 grains and 96 per cent of the total starch in 5 minutes ; 

 in about 94 per cent of the grains and 98 per cent of the 

 total starch in 15 minutes. (Chart D 217.) 



The reaction is rapid up to 15 minutes. Observation 

 was made at 3 minutes for comparison with other set. 

 The small percentage remaining after 15 minutes is very 

 resistant, very little change up to 60 minutes. 



The reaction with potassium iodide begins in a few 

 grains in 1 minute. Complete gelatinization occurs in 

 less than 0.5 per cent of the entire number of grains and 

 total starch in 5 minutes; in about 2 per cent of the 

 grains and 9 per cent of the total starch in 15 minutes; 

 in about 6 per cent of the grains and 25 per cent of the 

 total starch in 30 minutes; in about 31 per cent of the 

 grains and 47 per cent of the total starch in 45 minutes ; 

 little if any further advance in 60 minutes. (Chart 

 D218.) 



The hilum is very distinct and a bubble is never 

 formed there. The lamella?, also, are more distinct than 

 in any other of Nerine studied. Gelatinization begins at 

 the hilum which enlarges slowly. First the starch im- 

 mediately surrounding the hilum is divided by irregu- 

 lar radiating fissures into granules, and then 2 refractive 

 fissures, which branch at the distal end, extend from the 

 hilum to the distal margin. The portion of the grain 

 included between these 2 fissures becomes more hyaline 

 in appearance and then is divided into fine granules. As 

 the hilum continues to enlarge the more resistant starch 

 at the proximal end and sides forms a thick, refractive 

 marginal band, which is invaded by a number of cracks 

 from the margin and so divided into coarse granules. 

 The granules about the hilum gelatinize first, then the 

 fine granules between the hilum and the distal margin. 

 In the meantime the coarse granules at the proximal 

 margin become less distinctly separated from one an- 

 other, as they grow smaller and more transparent and 

 the marginal band of which they form a part becomes 

 thinner, more hyaline and more homogeneous in appear- 

 ance, until only the thin, nearly transparent capsule is 

 left. The gelatinized grains are very large and consider- 

 ably distorted and do not retain much resemblance to the 

 form of the untreated grain. 



The reaction with potassium sulphocyanate begins in 

 a few grains immediately. Complete gtelatinization 

 occurs in about 2 per cent of the entire number of grains 

 and 10 per cent of the total starch in 5 minutes; in 

 about 25 per cent of the grains and 46 per cent of the 

 total starch in 15 minutes; in about 48 per cent of the 

 grains and 78 per cent of the total starch in 30 minutes ; 

 in about 61 per cent of the grains and 83 per cent of 

 the total starch in 45 minutes ; in about 74 per cent of the 



grains and 90 per cent of the total starch in 60 minutes. 

 (Chart D 219.) 



The hilum is very distinct and a bubble is not formed 

 there in any of the grains. The lamella; are very distinct 

 and remain so throughout the greater part of the reac- 

 tion. Before gelatinization begins 2 fissures in the in- 

 terior of the grain extend out on either side nearly to 

 the distal margin, and the portion lying between them 

 becomes thinner and more refractive in appearance. 

 Gelatinization begins at the hilum which enlarges slowly, 

 and the starch immediately surrounding the hilum is 

 divided, by irregular fissuration, into coarse granules, 

 then the fissures before mentioned branch extensively 

 and divide the deposit at the distal end, lying between 

 them, into many rather fine granules irregularly 

 arranged; while the rest of the starch between the 

 hilum and the distal end is divided by striae into fine 

 granules in rows corresponding to the arrangement of 

 the lamella?. This granular material is then gelatinized 

 from the hilum distally, excepting the coarse granules 

 immediately about the hilum, which often persist until 

 the rest of the grain is gelatinized. In the meantime 

 the more resistant material at the proximal end and 

 sides forms a thick striated, but non-lamellated marginal 

 band which gradually grows thinner and more nearly 

 transparent until only the thin capsule is left. Then the 

 granules, mentioned before as the last to be gelatinized 

 and which after the swelling of the grain are arranged 

 around the inner border of the proximal marginal band, 

 are slowly gelatinized. 



The gelatinized grains are large and considerably 

 distorted, but retain some resemblance to the form of 

 the untreated grain. 



The reaction with potassium sulphide begins in a few 

 grains immediately. Complete gelatinization occurs in 

 about 3 per cent of the entire number of grains and 12 

 per cent of the total starch in 5 minutes; in about 

 22 per cent of the grains and 47 per cent of the total 

 starch in 15 minutes; in about 40 per cent of the grains 

 and 62 per cent of the total starch in 30 minutes; in about 

 43 per cent of the grains and 68 per cent of the total 

 starch in 45 minutes ; in about 47 per cent of the grains 

 and 71 per cent of the total starch in 60 minutes. (Chart 

 D220.) 



The hilum is very distinct, and the lamella? also are 

 very distinct and remain so at the proximal end during 

 the greater part of the reaction. Gelatinization begins 

 at the hilum which enlarges slowly, and at the same 

 time 2 refractive fissures appear which branch extensively 

 and extend from the hilum to the distal margin. As the 

 hilum continues to enlarge, the starch immediately sur- 

 rounding it is divided by irregular fissures into coarse 

 granules, and the lamella? between the two refractive 

 fissures are formed into rows of fine granules following 

 the lines of the lamellae, while the proximal deposit 

 forms a non-striated, lamellated marginal band which 

 in many grains is divided into portions of varying size 

 by the inversion of fissures already existing at the hilum, 

 which extend nearly to the margin. Later these portions 

 become striated and then divided into granules and, as 

 the grain continues to enlarge, the coarse granules which 

 were originally about the hilum are arranged more or less 

 regularly just within this marginal band. Gelatiniza- 



