642 



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



in 45 minutes; in more than 99 per cent of the grains 

 and total starch in 60 minutes. (Chart D 380.) 



The reaction with pyrogallic acid begins in 30 sec- 

 onds. Complete gelatinization occurs in less than 0.5 per 

 cent of the entire number of grains and 28 per cent of 

 the total starch in 5 minutes; in about 17 per cent of the 

 grains and 77 per cent of the total starch in 15 minutes; 

 in about 43 per cent of the grains and 84 per cent of the 

 total starch in 30 minutes; in about 52 per cent of the 

 grains and 93 per cent of the total starch in 45 minutes; 

 in about 64 per cent of the grains and 96 per cent of the 

 total starch in 60 minutes. (Chart D 381.) 



The reaction with nitric acid begins immediately. 

 Complete gelatinization occurs in about 18 per cent of 

 the entire number of grains and 70 per cent of the total 

 starch in 5 minutes ; in about 41 per cent of the grains 

 and 82 per cent of the total starch in 15 minutes; in 

 about 50 per cent of the grains and 86 per cent of the 

 total starch in 30 minutes; in about 59 per cent of the 

 grains and 90 per cent of the total starch in 45 minutes ; 

 in about 70 per cent of the grains and 93 per cent of the 

 total starch in 60 minutes. (Chart D 382.) 



The reaction with sulphuric acid begins immediately. 

 Complete gelatinization occurs in about 80 per cent of 

 the entire number of grains and 98 per cent of the total 

 starch in 2 minutes; in about 97 per cent of the grains 

 and in more than 99 per cent of the total starch in 5 

 minutes. (Chart D 383.) 



The reaction with hydrochloric acid begins imme- 

 diately. Complete gelatinization occurs in about 30 per 

 cent of the entire number of grains and 72 per cent of 

 the total starch in 5 minutes; in about 50 per cent of 

 the grains and 83 per cent of the total starch in 15 

 minutes; in about 78 per cent of the grains and 88 per 

 cent of the total starch in 30 minutes; little if any 

 further advance in 45 minutes, and about 90 per cent 

 in 60 minutes. (Chart D 384.) 



The hilum and lamellae both become more distinct 

 than in I. iberica. Gelatinization begins at the hilum and 

 is as in I. iberica preceded by the enlargement and exten- 

 sion of 2 refractive fissures which are usually already 

 present in the untreated grain; these fissures are much 

 more prominent, larger, and more branching than in /. 

 iberica. The material included between these fissures, 

 the hilum and the distal margin, become more refrac- 

 tive in appearance than in /. iberica and is divided 

 into coarse granules. Now the hilum enlarges, and 

 in a small majority of the grains the proximal starch 

 is the least resistant so that the hilum enlarges more 

 rapidly in that direction than toward the distal end. 

 The portion here and at the sides forms a finely striated 

 and distinctly lamellated marginal band which becomes 

 rapidly thinner and more nearly transparent. The distal 

 material is then gelatinized except a group of coarse, 

 refractive lamellae at the distal margin which remain 

 long after the rest of the grain is gelatinized. In the 

 rest of the grains the proximal, marginal band is gela- 

 tinized after the distal region, but in no grains are there 

 seen the coarse granules arranged around the inner bor- 

 der of this band such as were seen in I. iberica. 



The gelatinized grains are large and capsules have 

 thicker walls and are somewhat less distorted than in 

 /. iberica. There are fewer grains partially or com- 

 pletely dissolved than in /. iberica. 



The reaction with potassium hydroxide begins imme- 

 diately. Complete gelatinization occurs in about 44 per 

 cent of the entire number of grains and 84 per cent of 

 the total starch in 5 minutes; in about 68 per cent of 

 the grains and 92 per cent of the total starch in 15 min- 

 utes; in about 72 per cent of the grains and 96 per cent 

 of the total starch in 30 minutes; little if any further 

 advance in 45 and 60 minutes, respectively. (Chart 

 D 385.) 



The reaction with potassium iodide begins imme- 

 diately. Complete gelatinization occurs in about 24 

 per cent of the entire number of grains and 58 per cent 

 of the total starch in 5 minutes ; in about 58 per cent of 

 the grains and 83 per cent of the total starch in 15 

 minutes; in about 75 per cent of the grains and 92 per 

 cent of the total starch in 30 minutes ; in about 84 per 

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

 45 minutes; in about the same percentage of the grains 

 and 94 per cent of the total starch in 60 minutes. 

 (Chart D386.) 



The hilum is more distinct than in /. iberica, and 

 if 2 refractive fissures are already present in the un- 

 treated grain, they grow wider and more extensive, and 

 if they are not present, they form soon after the reagent is 

 added. The lamellae are more distinct than in I. iberica, 

 and remain visible longer. Gelatinization, as in I. iberica, 

 begins at the hilum, which enlarges somewhat, and the 2 

 fissures already described extend further toward the distal 

 margin, but in many grains they turn toward one 

 another before they reach the margin and unite so as to 

 completely separate the inner central part of the grain 

 from the marginal portion. In such grains the marginal 

 starch becomes more and more refractive and is gela- 

 tinized most rapidly at the proximal end, while the 

 inner portion is divided irregularly into numerous gran- 

 ules by irregular fissures, and may remain ungelatinized 

 for some time. In other grains, the process begins at 

 the hilum and extends down to the distal end, and the 

 most resistant starch is at the proximal end in some 

 grains, but at the distal end in others, this latter much 

 more frequently than in /. iberica, and in no case was 

 gelatinization observed to start, as in many grains of 

 /. iberica, at the distal margin first. 



The gelatinized grains are much swollen with thicker 

 capsules, and are not so distorted and retain more resem- 

 blance to the form of the untreated grain than in I. 

 iberica. 



The reaction with potassium sulphocyanate begins 

 immediately. Complete gelatinization occurs in about 

 48 per cent of the entire number of grains and 88 per 

 cent of the total starch in 2 minutes; in about 72 per 

 cent of the grains and 95 per cent of the total starch 

 in 5 minutes; in about 80 per cent of the grains and 

 98 per cent of the total starch in 15 minutes. (Chart 

 D387.) 



The reaction with potassium sulphide begins in 30 

 seconds. Complete gelatinization occurs in about 1 per 

 cent of the entire number of grains and 6 per cent of the 

 total starch in 5 minutes; in about 1 per cent of the 

 grains and 11 per cent of the total starch in 15 minutes; 

 in about 3 per cent of the grains and 16 per cent of the 

 total starch in 30 minutes; in about 5 per cent of the 

 grains and 20 per cent of the total starch in 45 minutes ; 



