456 



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



Gelatinization begins at the distal margin and proceeds 

 proximalwards, the proximal end being resistant in many 

 more grains than in C. moorei. The process is accom- 

 panied by distention and distortion of the capsule, but 

 the distention is much less rapid than in C. moorei. The 

 sharper definition of the lamella? and the appearance of 

 clefts may be observed in the refractive border at the 

 distal margin previous to gelatinization, although with 

 much less frequency than in C. moorei. 



The gelatinized grains are swollen and considerably 

 distorted, especially at the distal margin, but they are 

 less distorted than in C. moorei. At the end of the 

 reaction (CO minutes) most of the grains have not ad- 

 vanced beyond the early stages of the process ; the cleft at 

 the hilum remaining much enlarged and very refractive. 



The reaction with chromic acid begins in a few grains 

 in 1 minute. Complete gelatinization is observed in rare 

 grains, all are penetrated by deep fissures, and less than 

 1 per cent of the total starch is gelatinized in 5 min- 

 utes. Only rare grains and only about 2 per cent of the 

 total starch are gelatinized in 15 minutes. Only rare 

 grains and the mesial portions of all others and about 70 

 per cent of the total starch are gelatinized in 30 minutes. 

 About 50 per cent of the entire number of grains, con- 

 siderable portions of the other grains, and about 94 

 per cent of the total starch are gelatinized in 45 minutes. 

 More than 99 per cent of the total starch has been gela- 

 tinized in 60 minutes, the very small amount remaining 

 ungelatinized is found in parts of the margin of scattered 

 grains. ( Chart D 128.) 



The reaction with pyrogallic acid begins slowly, and 

 complete gelatinization occurs in only 1 per cent of the 

 entire number of grains and 3 per cent of the total starch 

 in 5 minutes; in about 6 per cent of the grains and 15 

 per cent of the total starch in 15 minutes; in about 45 

 per cent of the grains and 80 per cent of the total starch 

 in 30 minutes (13 per cent of the grains being un- 

 affected) ; in about 55 per cent of the grains and 88 per 

 cent of the total starch in 45 minutes (about 10 per cent 

 of the grains being but little affected) ; and in about 65 

 per cent of the grains and 92 per cent of the total starch 

 in 60 minutes (about 8 per cent of the grains remaining 

 but little affected). (Chart D 129.) 



The reaction with nitric acid begins in very few grains 

 in 2 minutes. Complete gelatinization occurs in only 

 rare grains and in about 1 per cent of the total starch iu 

 5 minutes ; in about 1 per cent of the entire number of 

 grains and 0.5 per cent of the total starch in 15 minutes ; 

 in about 1 per cent of the grains and 2 per cent of the 

 starch in 45 minutes ; and in about the same number 

 of grains and 4 per cent of the total starch in GO minutes. 

 (Chart D 130.) 



Gelatinization frequently begins along the distal mar- 

 gin and may proceed for a short distance at the sides 

 nearb}', accompanied by distention and fluting of the 

 capsule which appears as a delicate ruffle on a bordering 

 ungelatinized part of the grain. The main body of the 

 grain is disorganized along the course of the much- 

 branched fissures, accompanied by the breaking down of 

 the mesial region into a mass of very refractive granules. 

 These granules gradually become gelatinized, the most 

 resistant of them being located at the proximal end. The 

 capsule of most of the grains becomes dissolved at the 



distal margin, such grains being reduced largely to a 

 mass of very refractive granules irregularly scattered 

 towards the distal margin, but more compact towards the 

 proximal end, it being bounded at this end and sides 

 nearby by a narrow refractive band of lamella?. Scat- 

 tered among these grains are those having an entire un- 

 gelatinized margin and the shape of the untreated grain, 

 although the mesial portion is broken into a mass of 

 refractive granules. During gelatinization of the main 

 body of the grain there is a slight lateral protrusion at 

 the distal margin, followed by solution of this end, while 

 the proximal end retains its form and usually remains 

 ungelatinized. The rare completely gelatinized grains 

 are swollen and slightly distorted, having a general re- 

 semblance to the untreated grain. Comparison with C. 

 moorei: The mesial portion of the grain during disorgan- 

 ization is accompanied by the appearance of granules of 

 greater refractivity. A border at the distal margin is 

 more frequently gelatinized before the mesial region, 

 and a marginal border at the proximal end and sides is 

 the most resistant in both grains; gelatinization is not 

 complete in nearly so many grains, and when complete 

 the gelatinized grains exhibit much less distortion. 



The reaction with sulphuric acid begins in a few 

 grains in 1 minute. Complete gelatinization occurs in 

 about 2 per cent of the entire number of grains and 4 

 per cent of the total starch in 5 minutes ; in about 35 per 

 cent of the grains and 62 per cent of the total starch in 

 15 minutes; in about 50 per cent of the grains and 89 

 per cent of the total starch in 30 minutes, in about 65 

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

 45 minutes; and in about 85 per cent of the grains and 

 over 99 per cent of the total starch in 60 minutes (the 

 small percentage of starch ungelatinized is found in small 

 grains). (Chart D 131.) 



The reaction with hydrochloric acid begins in 2 min- 

 utes. None of the grains is wholly gelatinized and only 

 about 1 per cent of the total starch is disorganized in 5 

 minutes. Complete gelatinization occurs in about 1 per 

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

 total starch in 15 minutes; in about 2 per cent of the 

 grains and 14 per cent of the total starch in 30 minutes; 

 in about 3 per cent of the grains and 33 per cent of the 

 total starch in 45 minutes; and in about 4.5 per cent of 

 the grains and 35 per cent of the total starch in 60 

 minutes. (Chart D 132.) 



The reaction with potassium hydroxide begins in a 

 few grains in 1 minute. Complete gelatinization occurs 

 iu only rare grains and in about 1 per cent of the total 

 starch in 5 minutes; in about 3.5 per cent of the entire 

 number of grains and 5 per cent of the total starch in 15 

 minutes; in about 4 per cent of the grains and in 7 per 

 cent of the total starch in 30 minutes; in about 7 per 

 cent of the grains and 10 per cent of the total starch in 

 45 minutes ; and in about 8 per cent of the grains and 13 

 per cent of the total starch in 60 minutes. (Chart D 133.) 



The reaction with potassium iodide begins slowly. 

 Complete gelatinization is noted in only rare grains and 

 only about 1 per cent of the total starch is affected in 

 5 minutes. Very little progress is noted at the end of 

 15 minutes, the larger grains being the ones affected. 

 Complete gelatinization occurs in about 1 per cent of the 

 entire number of grains and 3 per cent of the total starch 



