752 



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



The reaction with potassium iodide begins imme- 

 diately. Complete gelatinization occurs in about 48 per 

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

 the total starch in 5 minutes ; in about 84 per cent of the 

 grains and 97 per cent of the total starch in 15 minutes; 

 in about 95 per cent of the grains and in over 99 per 

 cent of the total starch in 30 minutes. (Chart D 602.) 



The hilum becomes very distinct, as do the lamellae. 

 Gelatinization begins at the hilum which enlarges some- 

 what, and numerous branching fissures extend from the 

 hilum to the distal end, along the course of which the 

 starch loses its lamellar structure and becomes finely 

 granular, while around the proximal margin and sides 

 a very clearly defined, lamellated band of resistant starch 

 is formed. The granular portion of the grain is gela- 

 tinized first, with considerable distention and then in- 

 folding of the capsule ; the marginal band slowly becomes 

 thinner and more nearly transparent until only the thin 

 capsule is left. In the small grains and some of the large 

 grains granulation of one part does not take place, but a 

 marginal band is formed around the whole margin, and 

 these grains are less distorted than those first described. 

 The gelatinized grains are large, thin-walled, and often 

 more distorted at the distal end. They do not retain 

 much of the form of the untreated grain. 



The reaction with potassium sulphocyanate begins 

 immediately. Complete gelatinization occurs in about 

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

 of the total starch in 2 minutes; in about 90 per cent of 

 the grains and 99 per cent of the total starch in 5 min- 

 utes ; in about 98 per cent of the grains and in more than 

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

 D 603.) 



The reaction with potassium sulphide begins imme- 

 diately. Complete gelatinization occurs in about 53 per 

 cent of the entire number of grains and 83 per cent of 

 the total starch in 5 minutes; in about 57 per cent of the 

 grains and 87 per cent of the total starch in 15 minutes; 

 in about 59 per cent of the grains and 90 per cent of the 

 total starch in 30 minutes; in about 73 per cent of the 

 grains and 92 per cent of the total starch in 45 minutes ; 

 in about 80 per cent of the grains and 95 per cent of the 

 total starch in 60 minutes. (Chart D 604.) 



The reaction with sodium hydroxide begins imme- 

 diately. Complete gelatinization occurs in about 78 per 

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

 5 minutes; in about 96 per cent of the grains and in 99 

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

 D605.) 



The reaction with sodium sulphide begins immedi- 

 ately. Complete gelatinization occurs in about 43 per 

 cent of the grains and 79 per cent of the total starch in 

 5 minutes; in about 71 per cent of the grains and 89 

 per cent of the total starch in 15 minutes ; in about 83 

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

 in 30 minutes; in about 86 per cent of the grains and 

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

 further advance in 60 minutes. (Chart D 606.) 



The reaction with sodium salicylate begins imme- 

 diately. Complete gelatinization occurs in about 67 per 

 cent of the entire number of grains and 80 per cent of the 

 total starch in 5 minutes; in about 97 per cent of the 

 grains and 98 per cent of the total starch in 15 minutes. 

 ( Chart D 607.) 



The hilum becomes very distinct and a small bubble 

 is moderately often formed there. The lamellae become 

 distinct and remain so until gelatinized. A broad but not 

 very refractive band is quickly formed about the margins 

 of the grains. Gelatinization begins at two or three places 

 on the distal margin, at which points small cracks have 

 invaded, the grain, and in some grains the hilum and 

 proximal end are gelatinized immediately following this 

 beginning, but in most of the grains this does not take 

 place until after at least a third of the distal starch has 

 been gelatinized. Gelatinization proceeds moderately 

 smoothly and rather more rapidly around the margin 

 than in the central part of the grain, the part just distal 

 to the hilum being the most resistant in some grains; 

 when the rest of the starch has been gelatinized, this part 

 is split into two pieces by a fissure running from the 

 hilum distally, and these two pieces are rapidly gela- 

 tinized. In most of the grains, however, it is not so 

 split, but gelatinizes as a whole, and in a moderate number 

 of grains the proximal end is the last to be gelatinized. 

 The gelatinized grains are much enlarged, with somewhat 

 thick capsules, and much distorted. They do not retain 

 much of the form of the untreated grain. 



The reaction with calcium nitrate begins imme- 

 diately. Complete gelatinization occurs in about 25 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 95 per cent of the total starch in 15 minutes; 

 in about 80 per cent of the grains and 96 per cent of the 

 total starch in 30 minutes; in about 82 per cent of the 

 grains and 97 per cent of the total starch in 45 minutes; 

 in about 90 per cent of the grains and 98 per cent of the 

 total starch in 60 minutes. (Chart D 608.) 



The reaction with uranium nitrate begins imme- 

 diately. Complete gelatinization occurs in about 42 per 

 cent of the entire number of grains and 83 per cent of the 

 total starch in 5 minutes; in about 59 per cent of the 

 grains and 90 per cent of the total starch in 15 minutes ; 

 in about 95 per cent of the total starch in 10 minutes ; in 

 about 74 per cent of the grains and 95 per cent of the 

 total starch in 30 minutes; in about 85 per cent of the 

 grains and 96 per cent of the total starch in 45 minutes; 

 in about 90 per cent of the grains and 98 per cent of the 

 total starch in 60 minutes. (Chart D 609.) 



The reaction with strontium nitrate begins imme- 

 diately. Complete gelatinization occurs in about 70 per 

 cent of the entire number of grains and 91 per cent of the 

 total starch in 5 minutes; in about 95 per cent of the 

 grains and 99 per cent of the total starch in 15 minutes ; 

 in about 98 per cent of the grains and in more than 99 

 per cent of the total starch in 30 minutes. (Chart 

 D 610.) 



The reaction with cobalt nitrate begins in a few 

 grains in 30 seconds. Complete gelatinization occurs in 

 about 6 per cent of the entire number of grains and 16 

 per cent of the total starch in 5 minutes; in about 16 

 per cent of the grains and 46 per cent of the total starch 

 in 15 minutes; in about 18 per cent of the grains and 

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

 28 per cent of the grains and 56 per cent of the total 

 starch in 45 minutes ; in about 32 per cent of the grains 

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

 D611.) 



