588 



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



majority of the resistant grains than in N. leedsii minnie 

 hume, gelatinization begins at the distal margin and 

 progresses smoothly toward the hilum and proximal 

 end. It does not progress more rapidly around the 

 margin than in the interior of the grains as in N. leedsii 

 minnie hume, and the proximal end is the last part 

 of the grain to be gelatinized instead of the portion 

 just distal to the hilum as in N. leedsii minnie hume. 

 In the second method gelatinization begins at the distal 

 end and progresses from there smoothly up to the proxi- 

 mal end, or at the distal end and then at the proximal end, 

 as in N. leedsii minnie hume, and progresses smoothly 

 from these two points, the material just distal to the 

 hilum being the last to be gelatinized. 



The gelatinized grains are very much swollen and 

 have rather thin capsules. They are even more distorted 

 than in N. leedsii minnie hume. 



The reaction with chromic acid begins immediately. 

 Complete gelatinization occurs in about 1 per cent of the 

 entire number of grains and 5 per cent of the total 

 starch in 5 minutes ; in about the same percentage of the 

 grains and 20 per cent of the total starch in 15 minutes ; 

 in about 10 per cent of the grains and 70 per cent of 

 the total starch in 30 minutes; in about 43 per cent of 

 the grains and 94 per cent of the total starch in 45 

 minutes; and in about 53 per cent of the grains and 97 

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

 D 336.) (See footnote, page 516.) 



The hilum and lamellae are as distinct as in N. leedsii 

 minnie hume, and evidence of a lamellar structure per- 

 sists as long as in the grains of that starch. Gela- 

 tinization begins at the hilum and progresses according 

 to two methods, which are similar to the two described 

 under N. leedsii minnie hume. In the first, which is seen 

 in. a majority of the grains and which is similar to that 

 described for a large minority of those of N. leedsii 

 minnie hume, the primary starch around the hilum is 

 divided into very fine granules which are much finer 

 and less distinct than those in N. leedsii minnie hume, 

 and a sheaf of irregular fissures extends through the 

 secondary starch to the distal and proximal margins of 

 the grain. The remainder of the secondary starch is 

 divided by very coarse striae. The less resistant portion 

 of the secondary starch gelatinizes and the grain swells. 

 The more resistant starch forms a band at the margin 

 which is coarsely striated and lamellated and which is 

 not continuous, as the deposit at the proximal and the 

 distal ends is gelatinized quickly. The interior of the 

 grain is finely granular, and these granules are gela- 

 tinized before the marginal band, which slowly grows 

 thinner and more nearly transparent, retaining the 

 lamellar appearance until all the material is gelatinized. 

 In the second method, which is similar to that seen in a 

 small majority of the grains of N. leedsii minnie hume, 

 2 furrows or fissures extend transversely or obliquely 

 from either side of the hilum to the margin and the 

 material which is distal to them and to the hilum is 

 divided into a mass of rather fine refractive granules by 

 many irregular fissures and rather slowly gelatinizes 

 with much swelling but not much distortion of the cap- 

 sule. The proximal starch is divided by rather coarse 

 striae, and as the grain swells forms a coarsely striated 

 and lamellated band at the proximal margin, which is 

 even more slowly gelatinized than the distal material. 



The grains as in N. leedsii minnie hume are all gela- 

 tinized before they are dissolved. The gelatinized grains 

 are much swollen, have as thin capsules, and are no more 

 distorted than in N. leedsii minnie hume. 



The reaction with pyrogallic acid begins in 30 sec- 

 onds. Complete gelatinization occurs in about 1 per cent 

 of the entire number of grains and 4 per cent of the total 

 starch in 5 minutes ; in about 4 per cent of the grains 

 and 21 per cent of the total starch in 15 minutes; in 

 about 41 per cent of the grains and 78 per cent of the 

 total starch in 30 minutes; in about 56 per cent of the 

 grains and 85 per cent of the total starch in 45 minutes ; 

 and in about 67 per cent of the grains and 91 per cent 

 of the total starch in 60 minutes. (Chart D 337.) 



The hilum becomes as distinct as in N. leedsii minnie 

 hume, unattended by the formation of a bubble. The 

 lamella are moderately distinct, and evidence of a lamel- 

 lar structure is as distinct as in N. leedsii minnie hume. 

 Gelatinization begins at the hilum and follows three 

 methods of procedure. In the first, which is seen in 

 a large number of grains, which is not, however, a major- 

 ity of the whole number, 2 furrows or actual fissures 

 extend transversely or slightly obliquely from the hilum 

 on either side to the margin and the material distal to 

 them and to the hilum becomes a finely granular mass as 

 in N. leedsii minnie hume. This portion slowly gela- 

 tinizes, with some swelling of the grain, and the proximal 

 deposit is first covered by very fine and often rather 

 indistinct striae, but as the grain swells forms a homo- 

 geneous-looking, refractive band at the proximal margin, 

 which is gelatinized even more slowly than the distal 

 material, in many grains not reaching complete gelati- 

 nization. The second and third methods are seen in 

 equal numbers of the remaining grains. In the second 

 method the hilum enlarges somewhat and the grain is 

 covered by fine striae and gelatinizes slowly, the more 

 resistant starch forming a finely striated band at the 

 margin, which very slowly becomes thinner and more 

 nearly transparent until it is completely gelatinized. In 

 the third method the primary starch around the margin is 

 divided into a number of coarse granules which are 

 scattered as the grain swells. The secondary deposit is 

 covered with fine strise and the less resistant portion is 

 gelatinized, while the more resistant portion forms a 

 finely striated and lamellated marginal band, around 

 which are scattered the granules of the primary starch 

 and which slowly becomes thinner and more nearly trans- 

 parent, but in some grains is not completely gelatinized. 

 The gelatinized grains are as much swollen, have as thick 

 capsules, and are as much distorted as in N. leedsii 

 minnie hume. 



The reaction with nitric acid begins immediately. 

 Complete gelatinization occurs in about 1 per cent of the 

 entire number of grains and 10 per cent of the total 

 starch in 5 minutes; in about 7 per cent of the grains 

 and 32 per cent of the total starch in 15 minutes ; in about 

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

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

 and 59 per cent of the total starch in 45 minutes; and 

 in about 35 per cent of the grains and 62 per cent of the 

 total starch in 60 minutes. (Chart D 339.) 



The hilum is as distinct as in N. leedsii minnie hume 

 and the lamellae are moderately distinct, but not so dis- 

 tinct as in N. leedsii minnie hume, but evidence of a 



