468 



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



per cent of the entire number of grains and 70 per cent 

 of the total starch in 3 minutes; in about 77 per cent of 

 the grains and 93 per cent of the total starch in 5 min- 

 utes ; in about 80 per cent of the grains and 94 per cent 

 of the total starch in 10 minutes; in about the same per- 

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

 15 minutes; in about 95 per cent of the grains and 99 

 per cent of the total starch in 30 minutes; and in all 

 of the starch except minute parts of the extreme margin 

 of rare grains in 60 minutes. The proximal end of the 

 larger grains and scattered smaller grains are the most 

 resistant, and the proximal end and sides of the plane 

 surface of a few plano-convex grains are very resistant. 

 (Chart D 156.) 



The fissures enlarge and become very dark and refrac- 

 tive, but this refractivity is quickly lost, accompanied 

 by the expulsion of a large bubble. The latter occurs 

 much more quickly and the bubble is much larger and 

 more commonly present than in C. zeylanicum. A refrac- 

 tive band is observed near the distal margin in which the 

 lamellae are much less sharply defined than in C. zey- 

 lanicum. Gelatinization is usually much more rapid 

 in the mesial portion at the area around the hilum than at 

 other parts, and the refractive distal band breaks up into 

 more refractive granules and is the more resistant. This 

 is the reverse of that which is commonly noted in C. 

 zeylanicum. The granules, however, throughout the 

 grain are usually less refractive than in C. zeylanicum. 

 The narrow band consisting of a few lamellae at the proxi- 

 mal end and sides nearby is the most resistant, as in 

 C. zeylanicum. The grains are with rare exceptions 

 completely gelatinized, whereas complete gelatinization 

 is rare in C. zeylanicum. The grains are much swollen 

 and but little distorted so that they bear a general resem- 

 blance to the untreated grain. 



The reaction with potassium sulphide begins imme- 

 diately and a few scattered grains are gelatinized in 1 

 minute. Complete gelatinization occurs in about 30 

 per cent of the entire number of grains and 50 per cent 

 of the total starch in 5 minutes ; in about 33 per cent of 

 the grains and 55 per cent of the total starch in 15 min- 

 utes ; in about 40 per cent of the grains and 60 per cent 

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

 centage of grains and of total starch in 45 minutes ; and 

 in about 46 per centi of the grains and 66 per cent of the 

 total starch in 60 minutes. (Chart D 157.) 



A bubble forms at the hilum and it may be within 

 an enlarged refractive cleft and often expand to a con- 

 siderable size. It is inclosed much less frequently but it 

 expands more than in C. zeylanicum. The lamellae some- 

 times become sharply defined over the entire grain but 

 commonly one lamella, which appears at varying dis- 

 tances from the hilum, is much more distinct than the 

 others. A band distal to this lamella becomes more re- 

 fractive than the area proximal to it ; the lamellae forming 

 this distal band become gradually more sharply defined 

 and striated, and both the increased definition and stria- 

 tion appear in a larger percentage of grains than in C. 

 zeylanicum. Fissures which proceed from the hilum are 

 much branched, as in C. zeylanicum, but they are less 

 deep and exhibit more variation in number and direction 

 than in C. zeylanicum. Two such fissures extend almost 

 transversely toward the corners of the plano-convex 

 grains, which fissures are quite characteristic of C. longi- 



folium but not found in C. zeylanicum. Gelatinization 

 begins more frequently in a distal border than in C. zey- 

 lanicum, probably due to the frequency of this method of 

 gelatinization as in the plano-convex grains which are 

 not found in C. zeylanicum. The gelatinization of these 

 plano-convex grains is, however, variable, since in some 

 of them it proceeds distalward from the hilum, while in 

 a larger percentage it begins at the distal convex border. 

 The mesial portion of the grains is often disorganized, 

 accompanied by the appearance of refractive granules, 

 though not in so large a percentage of grains as in C. 

 zeylanicum, hence the mean refractivity is less than in 

 C. zeylanicum. The most resistant portion usually con- 

 sists of a narrow, striated, refractive border at the proxi- 

 mal end and sides nearby, as noted in C. zeylanicum, but 

 this border is not so broad and it exhibits less resistancy 

 than in C. zeylanicum. The gelatinized grains are much 

 swollen and slightly to much distorted, the distortion 

 being more marked at the distal margin. The distortion 

 is greater on the whole than in C. zeylanicum and hence 

 the grains bear less resemblance to the untreated grains 

 than in the latter. 



The reaction with sodium hydroxide begins imme- 

 diately and many grains are fully gelatinized in 1 min- 

 ute. Complete gelatinization occurs in about 75 per cent 

 of the entire number of grains and 90 per cent of the 

 total starch in 3 minutes; in about 80 per cent of the 

 grains and 91 per cent of the total starch in 3 min- 

 utes; in about 85 per cent of the grains and 95 per 

 cent of the total starch in 15 minutes; in about 93 

 per cent of the grains and 98 per cent of the total 

 starch in 30 minutes; in about the same percentage 

 of each in 45 minutes; and in about 95 per cent of 

 the grains and 99 per cent of the total starch in 60 

 minutes. The resistant starch is located in the proximal 

 end of a few of the larger grains and in rare smaller 

 grains. (Chart D 158.) 



The reaction with sodium sulphide begins immedi- 

 ately. Complete gelatinization occurs in about 46 per 

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

 the total starch in 5 minutes; in about 50 per cent of 

 the grains and 66 per cent of the total starch in 15 min- 

 utes ; in about 58 per cent of the grains and 82 per cent 

 of the total starch in 30 minutes; in about 63 per cent 

 of the grains and 84 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 159.) 



A bubble appears at the hilum and is frequently 

 inclosed within an enlarged fissure. The bubble fre- 

 quently expands to a large size, and to a greater degree 

 than in C. zeylanicum. A few lamellae become more dis- 

 tinct, as in C. zeylanicum. The refractive border at the 

 distal margin (often extending around the entire grain) 

 may become very prominent in more grains than in 

 C. zeylanicum. Fissures form which are profusely 

 branched, as in C. zeylanicum, but they are generally not 

 so deep. The mesial region is usually disorganized with 

 slightly to fairly refractive granules, a few very refractive 

 granules being scattered -along the course of fissures. 

 They are less refractive than in C. zeylanicum. The dis- 

 tal margin is often gelatinized first, without the appear- 

 ance of granules and accompanied with much convoluted 

 distortion more frequently than in C. zeylanicum. In 

 other grains this refractive border may be the most resist- 



