500 



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



in 15 minutes ; in about 0.5 per cent 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 7 per 

 cent of the total starch in 60 minutes. (Chart D 218.) 



The hilum and lamellae are very distinct, but not so 

 distinct as in N. bowdeni. Gelatinization, as in N. bow- 

 deni, begins at the hilum which enlarges very slowly, 

 and the material immediately surrounding the hilum is 

 divided into fine granules by fine, regular, radiating fis- 

 sures. As gelatinization progresses, the lamellae from the 

 hilum to the distal margin are serially divided into gran- 

 ules and then gelatinized, while the more resistant mate- 

 rial at the proximal end and sides forms a lamellated, 

 faintly striated marginal band which is later broken up 

 into granules by fissures, and the granules in turn are 

 separated into groups by fan-shaped fissures from within. 

 The outer part of this marginal band grows thinner and 

 more nearly transparent as gelatinization proceeds, leav- 

 ing an inner row of granules which persist long after 

 the rest of the grain is gelatinized ; in some grains these 

 also are finally gelatinized. The gelatinized grains are 

 large but are not so much distorted as in N. bowdeni. 



The reaction with potassium sulphocyanate begins 

 in a few grains immediately. Complete gelatinization 

 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 about 0.5 per cent of the grains and 7 per cent of the 

 total starch in 15 minutes; in about 3 per cent of the 

 grains and 19 per cent of the total starch in 30 minutes ; 

 in about 12 per cent of the grains and 29 per cent of the 

 total starch in 45 minutes; in about 20 per cent of the 

 grains and 50 per cent of the total starch in 60 minutes. 

 (Chart D 219.) 



The hilum is distinct, but not so distinct as in 2V. 

 bowdeni, and the lamellae also are not so distinct as in 

 this species, but are distinct and remain so during the 

 greater part of the reaction. Gelatinization begins at the 

 hilum as in 2V. bowdeni, but is not preceded by the 

 extension of 2 fissures in the interior of the grain from 

 the hilum to the distal end as in 2V. bowdeni. Such fis- 

 sures do appear, but not until late in the reaction and are 

 not extensive and do not branch at all. The grain does 

 not become fissured nor granular as in 2V. bowdeni, 

 and gelatinization usually occurs first at the proximal 

 end and then at the distal end rather than first at the 

 distal end as in 2V. bowdeni. The gelatinized grains are 

 large and somewhat distorted, but not so much as in 

 2V. bowdeni. 



The reaction with potassium sulphide begins imme- 

 diately. Complete gelatinization occurs in about 23 per 

 cent of the entire number of grains and 52 per cent of 

 the total starch in 5 minutes; in about 47 per cent of 

 the grains and 67 per cent of the total starch in 15 

 minutes; in about 54 per cent of the grains and 72 

 per cent of the total starch in 30 minutes; in about 58 

 per cent of the grains and 77 per cent of the total starch 

 in 45 minutes; in about G3 per cent of the grains and 

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

 D220.) 



The hilum and lamellae are distinct, but less distinct 

 than in 2V. bowdeni. Gelatinization as in 2V. bowdeni 



begins at the hilum and two methods of procedure are 

 noted. In the first, which occurs in the greater number 

 of grains, the hilum enlarges smoothly in the direction 

 of the proximal end as the starch here is less resistant 

 than that at the distal end, and a thin homogeneous- 

 looking refractive band is formed at the proximal mar- 

 gin by the last two or three lamellae which are more re- 

 sistant than the rest. This gradually becomes thinner 

 and more nearly transparent until only the capsule is left. 

 In the meantime the distal starch becomes indistinctly 

 granular, and at the same time its lamellar arrangement 

 is gelatinized from the hilum outwards, forming at last 

 a homogeneous-looking mass at the distal margin which 

 is the last part of the grain to be gelatinized. In the 

 second method which occurs in the more resistant grains, 

 the starch at the hilum is split into granules as it begins 

 to enlarge, and gelatinization often occurs first in the 

 distal material as in 2V. bowdeni. In a few of the grains 

 there is dissolution of the capsule at one point as in 

 2V. bowdeni, but this is of much less frequent occurrence 

 than in 2V. boivdeni. 



The gelatinized grains are large and thin-walled and 

 are not nearly so much distorted as in 2V. bowdeni, and 

 retain some resemblance to the form of the untreated 

 grain. 



The reaction with sodium hydroxide begins in a few 

 grains in half a minute. Complete gelatinization occurs 

 in about 1 per cent of the entire number of grains and 

 3 per cent of the total starch in 5 minutes ; in about 3 

 per cent of the grains and 5 per cent of the total starch 

 in 15 minutes; in about 8 per cent of the grains and 

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

 11 per cent of the grains and 18 per cent of the total 

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

 starch in 60 minutes. (Chart D 221.) 



The reaction with sodium sulphide begins in a few 

 grains in 1 minute. Complete gelatinization occurs in 

 about 0.5 per cent of the entire number of grains and 2 per 

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

 of the grains and 4 per cent of the total starch in 15 

 minutes ; in about 2 per cent of the grains and 5 per cent 

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

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

 in 45 minutes ; in about 3 per cent of the grains and 8 per 

 cent of the total starch in 60 minutes. (Chart D 222.) 



The reaction with sodium salicylate begins in half 

 a minute. Complete gelatinization occurs in about 77 

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

 of the total starch in 5 minutes; in about 96 per cent 

 of the grains and 99 per cent of the total starch in 

 10 minutes. (Chart D 223.) 



The hilum becomes distinct, but not so distinct as 

 in 2V. bowdeni, and a bubble is never observed to be 

 formed there. The lamella are distinct, but not so dis- 

 tinct as in 2V. bowdeni, and a narrow refractive band 

 which is more refractive than in 2V. bowdeni is slowly 

 formed about the margins of the grains. Gelatinization, 

 differing from 2V. bowdeni, usually begins at the proxi- 

 mal end, and in a few grains this is followed by gela- 

 tinization of the distal end, but usually gelatinization 

 progresses from the proximal to the distal end, in the 

 manner described in 2V. boivdcni, except that the margin 



