472 



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



and the variations of depth in the different grains, are 

 not so great as in C. zeylanicum, but somewhat more 

 marked than in C. longifolium. The mean coloration of 

 the grains is closer to C. zeylanicum. 



Temperature Reactions. 

 The temperature of gelatinizalion of the majority 

 of grains is 75° to 76°, and of all but rare resistant 

 grains at 77° to 79° C, mean 78° C. The reactions are 

 intermediate between those of the parents, but distinctly 

 nearer those of C. zeylanicum. 



Effects of Various Reagents. 



The reaction with chloral hydrate begins in very rare 

 grains in 2 minutes. Complete gelatinization occurs in 

 less than 0.5 per cent of the entire number of grains 

 and the total starch in 5 minutes; in less than 0.5 per 

 cent of the entire number of grains and 1 per cent 

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

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

 total starch in 30 minutes; in about 3 per cent of the 

 grains and 4 per cent of the total starch in 45 minutes, 

 with little if any further change in 60 minutes. (Chart 

 D 148.) 



Either a bubble appears at the hilum, or the fissure 

 thereat becomes very much enlarged and very refractive. 

 The enlarged fissure is more commonly present than the 

 uninclosed bubble, although the latter is a little more 

 often seen than in 0. zeylanicum but considerably less 

 than in C. longifolium. The lamellae immediately be- 

 come more distinct over a larger area of the grain than 

 in the parents. A refractive border is formed similar to 

 that noted in the parents; but a very brilliant lamella 

 may form a line of demarcation between the border and 

 the main body of the grain, this being more frequently 

 observed than in G. zeylanicum, but somewhat less often 

 than in C. longifolium. The border is broader around 

 the entire margin in a larger number of grains than in 

 C. zeylanicum but not in nearly so many as in C. longi- 

 folium. Gelatinization begins at the distal margin as in 

 both parents, and is accompanied by greater distention 

 but less distortion. The process was not observed to 

 extend around the entire margin, thus much more closely 

 following the method observed in C. zeylanicum than in 

 C. lo7igifolium. 



The gelatinized grains are swollen as in the parents, 

 but are much less distorted. Very few grains arc affected 

 by the reagent beyond the initial stages, about the same 

 as in C. zeylanicum, but much less than in C. longifolium. 

 The fissure remains very much enlarged and very refrac- 

 tive, and if the bubble at the hilum is not inclosed within 

 a cleft it also is large and very persistent. The qualita- 

 tive reactions show a closer relationship to those observed 

 in C. zeylanicum than in C. longifolium. 



The reaction with chromic acid begins in a few grains 

 in 1 minute. Rare grains are gelatinized, there is deep 

 penetration by branched fissures, and less than 1 per cent 

 of the total starch is gelatinized in 5 minutes. Com- 

 plete gelatinization occurs in less than 1 per cent of the 

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

 in 15 minutes (the fissures are very deep and branched) ; 

 in about 35 per cent of the grains and about 80 per cent 

 of the total starch in 30 minutes; in all grains except a 

 part of the margin of rare grains and over 99 pel cent 



of the total starch in 45 minutes ; and in all of the starch 

 in 60 minutes. (Chart D 149.) 



The reaction with pyrogallic acid begins in half a 

 minute. Complete gelatinization occurs in nearly 33 per 

 cent of the total starch, chiefly entire grains, in 5 min- 

 utes; in about 70 per cent of the entire number of grains 

 and about 87 per cent of the total starch in 15 minutes, 

 about 10 per cent of the grains being but little affected; 

 in about 75 per cent of the grains and 96 per cent of the 

 total starch in 30 minutes; in about 83 per cent of the 

 grains and 98 per cent of the total starch in 45 minutes ; 

 and in about the same percentage of each in 60 minutes. 

 (Chart D 150.) 



The reaction with nitric acid begins in half a minute. 

 Complete gelatinization occurs in about 3 per cent of the 

 entire number of grains and 7 per cent of the total starch 

 in 5 minutes ; in about 7 per cent of the grains and 30 per 

 cent of the total starch in 15 minutes ; and in about 17 per 

 cent of the grains and over 50 per cent of the total starch 

 in 30 minutes; in about 24 per cent of the grains and 61 

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

 40 per cent of the grains and 73 per cent of the total 

 starch in 60 minutes. (Chart D 151.) 



Gelatinization begins at the distal margin in the form 

 of a rapid swelling, accompanied by considerable distor- 

 tion and great distention of the capsule, which latter be- 

 come hyaline and several times the volume of the ungela- 

 tinized parts. This process then often proceeds laterally 

 and occasionally even in a narrow band at the proximal 

 end previous to the gelatinization of the area between the 

 hilum and distal gelatinized border. There is usually 

 much greater distention of the capsule at the distal and 

 the lateral than at the proximal margin in grains which 

 are gelatinized as noted above. The capsule at the distal 

 margin frequently becomes distended and slightly to con- 

 siderably frilled, the distention being greater but ex- 

 hibiting less frilling than noted in C. zeylanicum, though 

 more than in C. longifolium. As the reaction proceeds 

 proximally from the distal gelatinized border, a series 

 of crescentic clefts parallel to the distal border are 

 formed, which were not observed in either parent. In 

 other respects the processes of gelatinization more closely 

 follow those of C. zeylanicum than of G. longifolium. 



The gelatinized and semi-gelatinized grains are swol- 

 len and somewhat distorted, being about the same as in 

 C. zeylanicum, but less distorted and less fully gelatinized 

 than in C. longifolium. The qualitative reactions ex- 

 hibited a closer relationship to C. zeylanicum than C. 

 longifolium. 



The reaction with sulphuric acid begins in a few 

 grains in half a minute. Complete gelatinization occurs 

 in about 15 per cent of the entire number of grains and 

 40 per cent of the total starch in 5 minutes; in about 56 

 per cent of the grains and 87 per cent of the total starch 

 in 15 minutes ; and about 70 per cent of the grains and 

 96 per cent of the total starch in 30 minutes ; and in about 

 98 per cent of the grains and 99 per cent of the starch 

 in 45 minutes. Only a very narrow border at the proxi- 

 mal end and very little on the sides of few of the grains 

 remain ungelatinized, and even at the end of 60 min- 

 utes some traces of ungelatinized starch remain. (Chart 

 D 152.) 



The reaction with hydrochloric acid begins imme- 

 diately. Complete gelatinization occurs in about 2.5 



