658 



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



grains than in 7. pallida queen of may. The lamellae 

 are rather indistinct, but are visible in many more grains 

 than in 1. pallida queen of may. The grains become 

 more refractive after the addition of the reagent, and the 

 first portion of the grain to show this is a rather narrow 

 band of starch around the margin, which is, however, 

 not so narrow and much more refractive than in /. pal- 

 lida queen of may. Gelatinization as in I. pallida queen 

 of may begins at the corners of the distal margin and 

 spreads all along the distal margin from these points, but 

 unlike in that starch it proceeds smoothly without the 

 appearance of longitudinal fissures extending toward the 

 hilum from the distal end; also it usually proceeds with 

 equal rapidity along the margin and in the interior of the 

 grains, but in some grains it proceeds more rapidly in 

 the interior than along the margin. This is not seen 

 in /. pallida queen of may. 



The gelatinized grains are as much swollen, have 

 somewhat less thick capsules, and are not so much dis- 

 torted as in 7. pallida queen of may. 



The reaction with chromic acid begins in 1 minute. 

 Complete gelatinization occurs in less than 0.5 per cent 

 of the entire number of grains and 5 per cent of the 

 total starch in 5 minutes; in about 11 per cent of the 

 grains and 40 per cent of the total starch in 15 minutes; 

 in about 24 per cent of the grains and 81 per cent of 

 the total starch in 30 minutes; in about 49 per cent of 

 the grains and 95 per cent of the total starch in 45 

 minutes; in about 68 per cent of the grains and 98 per 

 cent of the total starch in CO minutes. (Chart D 422.) 



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 4 per cent 

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

 of the grains and 30 per cent of the total starch in 15 

 minutes; in about 16 per cent of the grains and 67 

 per cent of the total starch in 30 minutes ; in about 28 

 per cent of the grains and 84 per cent of the total starch 

 in 45 minutes; in about 36 per cent of the grains and 

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

 D423.) 



The reaction with nitric acid begins immediately. 

 Complete gelatinization occurs in about 1 per cent of 

 the entire number of grains and 9 per cent of the total 

 starch in 5 minutes; in about 21 per cent of the grains 

 and 62 per cent of the total starch in 15 minutes; in 

 about 34 per cent of the grains and 70 per cent of the 

 total starch in 30 minutes ; in about 39 per cent of the 

 grains and 79 per cent of the total starch in 45 minutes ; 

 in about 42 per cent of the grains and 81 per cent of the 

 total starch in 60 minutes. (Chart D 424.) 



The reaction with sulphuric acid begins immediately. 

 Complete gelatiuizatiou occurs in about 59 per cent of 

 the entire number of grains and 89 per cent of the total 

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

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

 minutes. ( Chart D 425.) 



The reaction with hydrochloric acid begins imme- 

 diately. Complete gelatinization occurs in about 24 per 

 cent of the entire number of grains and 64 per cent of 

 the total starch in 5 minutes ; in about 32 per cent of 

 the grains and 80 per cent of the total starch in 15 min- 

 utes ; in about 44 per cent of the grains and 84 per cent 

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



centage of both the grains and total starch in 45 min- 

 utes ; in about the same percentage of the grains and 86 

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

 D426.) 



The hilum becomes distinct in all the grains. The 

 lamella; also are very distinct. Two fissures which ex- 

 tend from the hilum to the distal margin and which pre- 

 exist in the untreated grain, become more distinct, and 

 the starch included between them is divided by rather 

 indistinct fissures into large irregular granules. Gela- 

 tinization begins at the distal end of the grain and 

 advances toward the hilum. As the grain swells the 

 rather indistinct, irregular fissures become more distinct 

 and separate the granules more widely. The portion 

 at the proximal margin and sides, which is very definitely 

 separated from the other part of the grain, forms a 

 homogeneous-looking baud at the margin. This, as the 

 grain continues to swell, is often invaded by short straight 

 cracks proceeding from the hilum at regular intervals. 

 After the starch comprehended between the 2 original 

 fissures is completely gelatinized, this marginal band 

 grows progressively thinner and more nearly transparent 

 until it is completely gelatinized and only the capsule 

 remains. The gelatinized grains are much swollen, have 

 rather thin capsules, and are not greatly distorted. 



Comparison of the hydrochloric-acid reactions be- 

 tween 7. cengialti and 7. pallida queen of may shows: 



The hilum and lamella; are somewhat more distinct 

 than in I. pallida queen of may. Gelatinizatiou begins 

 at the hilum and progresses according to two methods. 

 The first, which is seen in a majority of the grains, differs 

 from that described for all the grains of 7. pallida queen 

 of may in the following points : Gelatinization begins 

 at the distal margin, and then at the hilum, and the 

 most resistant portion, that which is comprehended be- 

 tween the two pre-existing fissures from the hilum, is 

 midway between the hilum and the distal end, instead 

 of just at the hilum, as in 7. pallida queen of may; the 

 granules into which this material is originally divided 

 are finer and less irregular in arrangement than those 

 of I. pallida queen of may. In the second method the 

 difference noted is that gelatinization begins at the hilum 

 and proceeds from there to the distal margin. In both 

 methods the marginal band at the proximal end and sides 

 nearby is indistinctly striated and lamellated instead of 

 being homogeneous in appearance as in 7. pallida queen 

 of may. 



The gelatinized grains are more swollen, have some- 

 what less thin capsules, and are somewhat less distorted, 

 than in 7. pallida queen of may. 



The reaction with potassium hydroxide begins im- 

 mediately. Complete gelatinization occurs in about 24 

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

 of the total starch in 5 minutes ; in about 44 per cent of 

 the grains and 86 per cent of the total starch in 15 

 minutes; in about 51 per cent of the grains and 90 per 

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

 same percentage of the grains and 91 per cent of the total 

 starch in 45 minutes ; in about the same percentage of the 

 grains and 93 per cent of the total starch in 60 minutes. 

 ( Chart D 427.) 



The reaction with potassium iodide begins imme- 

 diately. Complete gelatinization occurs in about 10 per 

 cent of the entire number of grains and 30 per cent of 



