510 



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



material at the proximal end in the meantime forms a 

 dense refractive baud at the proximal margin and sides, 

 and this is broken into granules by cracks from the mar- 

 gin and is gelatinized from the margin inward. The 

 gelatinized grains are large, thin-walled, and usually 

 somewhat less distorted than those of N. sarniensis var. 

 cornsca major. 



The reaction with sulphuric acid begins immediately. 

 Complete gelatinization occurs in about 77 per cent of 

 the entire number of grains and 97 per cent of the total 

 starch in 1 minute; in about 97 per cent of the grains 

 and 99 per cent of the total starch in 3 minutes; in about 

 99 per cent of the grains and in more than 99 per cent 

 of the total starch in 5 minutes. (Chart D 236.) 



The reaction with hydrochloric acid begins imme- 

 diately. Complete gelatiuization occurs in about 29 per 

 cent of the entire number of grains and 76 per cent of 

 the total starch in 5 minutes; in about 86 per cent of 

 the grains and 98 per cent of the total starch in 15 min- 

 utes; in about 95 per cent of the grains and 99 per cent 

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

 advance in 45 and 60 minutes, respectively. (Chart 

 D237.) 



The reaction with potassium hydroxide begins im- 

 mediately. Complete gelatinization occurs in about 95 

 per cent of the entire number of grains and 97 per cent 

 of the total starch in 3 minutes; in about 97 per cent 

 of the grains and in more than 99 per cent of the total 

 starch in 5 minutes; in about 98 per cent of the grains 

 and in more than 99 per cent of the total starch in 15 

 minutes. ( Chart D 238.) 



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

 0.5 per cent of the grains and 2 per cent of the total starch 

 in 15 minutes; in about the same percentage of the 

 grains and 3 per cent of the total starch in 30 minutes; 

 in about 1 per cent of the grains and 4 per cent of the 

 total starch in 45 minutes; in about 2 per cent of the 

 grains and 5 per cent of the total starch in 60 minutes. 

 (Chart D 239.) 



The hilum and lamella? are distinct but not so dis- 

 tinct as in N. sarniensis var. corusca major. Gelatiniza- 

 tion, as in N. sarniensis var. corusca major, begins at 

 the hilum, which enlarges very slowly, and the starch 

 immediately surrounding the hilum is divided by irregu- 

 lar, radiating fissures into granules; then 2 refractive 

 fissures extend distally from the hilum, and these do not 

 branch out and divide the surrounding material into 

 granules, but extend straight down and enlarge as the 

 hilum does. In the meantime the portion included be- 

 tween them becomes more hyaline and homogeneous in 

 appearance and finally is gelatinized with some enlarge- 

 ment of the grain. The more resistant starch at the 

 proximal end and sides forms a lamellated band which 

 is invaded by cracks from the margin and so divided 

 in rather fine granules. These may finally gelatinize, 

 but do not always. In some grains one of the fissures 

 extending from the hilum curves sidewise to the mar- 

 gin, and gelatinization first takes place here rather 

 than at the distal end. The gelatinized grains, of which 



there are very few, are large and somewhat more dis- 

 torted than in N. sarniensis var. corusca major. 



The reaction with potassium sulphocyanate begins 

 in a few grains immediately. Complete gelatiuization 

 occurs in less than 0.5 per cent of the entire number of 

 grains and 2 per cent of the total starch in 5 minutes; 

 in less than 0.5 per cent of the grains and 3 per cent of 

 the total starch in 15 minutes; in about 1 per cent of 

 the grains and 4 per cent of the total starch in 30 min- 

 utes ; very slight progress in 45 minutes ; in about 2 per 

 cent of the grains and 6 per cent of the total starch in 

 60 minutes. (Chart D 240.) 



The hilurn is as distinct as in N. sarniensis var. 

 corusca major, and the lamella? are less distinct than in 

 N. sarniensis var. corusca major and do not remain dis- 

 tinct throughout the greater part of the reaction as in 

 those grains. Gelatinization is preceded by the appear- 

 ance in the interior of the grain of 2 fissures which ex- 

 tend from the hilum nearly to the distal margin. Gela- 

 tinization begins at the hilum as in N. sarniensis var. 

 corusca major and proceeds in two ways, an approxi- 

 mately equal number of grains being gelatinized in each 

 way. In one the distal starch is the least resistant, 

 and becomes refractive in appearance, and is divided by 

 branches from the two fissures, already mentioned, into 

 fine granules, and then gelatinized from the hilum dis- 

 tally, while the more resistant proximal portion forms 

 a thick non-striated, non-larnellated band which grows 

 slowly thinner and more nearly transparent until all is 

 gelatinized and only the thin capsule remains. In the 

 other the process is the same as that described under 

 N. sarniensis var. corusca major. 



The gelatinized grains are large and as a rule some- 

 what less distorted than in N. sarniensis var. corusca 

 major, and retain more of a resemblance to the form 

 of the untreated grain. 



The reaction with potassium sulphide begins imme- 

 diately in a few grains. Complete gelatinization occurs 

 in about 4 per cent of the entire number of grains and 

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

 37 per cent of the entire number of grains and 65 per 

 cent of the total starch in 15 minutes; in about 58 per 

 cent of the grains and 70 per cent of the total starch in 

 30 minutes; in about 66 per cent of the grains and 74 

 per cent of the total starch in 45 minutes; in about 69 

 per cent of the grains and 76 per cent of the total starch 

 in 60 minutes. (Chart D 241.) 



The hilum and lamella? are distinct, but not so dis- 

 tinct as in N. sarniensis var. corusca major. Gelatiniza- 

 tion begins at the hilum as in N. sarniensis var. corusca 

 major. As the hilum begins to enlarge, 2 refractive fis- 

 sures extend distally from the hilum towards the distal 

 margin but do not branch out at all. The material 

 at the proximal end is in a small majority the least 

 resistant as in N. sarniensis var. corusca major, and 

 gelatinization occurs there first, and then the distal 

 starch is gelatinized without fissuring or granulation 

 from the hilum outwards. Near the end of the reaction, 

 when there is only a small mass of material remaining 

 at the distal margin, some striation and granulation is 

 noted, and in a few grains fine granules are formed from 

 the material immediately surrounding the hilum, and 

 these are more resistant than the rest of the grain. In 



