402 



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



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

 starch in GO minutes. (Chart D 24.) 



The reaction with nitric acid begins in a few grains 

 immediately. Complete gelatinization occurs in about 

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

 of the total starch in 5 minutes; in about 20 per cent 

 of the entire number of grains and 25 per cent of the 

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

 grains and 49 per cent of the total starch in 30 minutes ; 

 in about 32 per cent of the grains and 60 per cent of the 

 total starch in 45 minutes; in about 40 per cent of the 

 grains and 75 per cent of the total starch in 60 minutes. 

 (Chart D 25.) 



The hilum swells but no bubble was detected thereat 

 as in H. titan. The entire grain becomes very refrac- 

 tive, and the definition of the lamellae and refractive 

 border are about the same as in H. titan. Fissures of a 

 similar character are formed but they are not so deep 

 nor so much branched as in II. titan. The various 

 methods of gelatinization noted in H. clconia are ob- 

 served; but the reaction starts at the distal margin and 

 advances towards the proximal end in fewer grains, and 

 the pitted appearance preceding gelatinization and the 

 slashing of the capsule at several points at the end of 

 gelatinization is found in more grains than in H. titan. 

 Gelatinization is preceded by the formation of very 

 refractive granules which are much less resistant than in 

 H. titan, and partial or complete solution may follow 

 gelatinization as in II. titan. 



The gelatinized grains are swollen and slightly to 

 considerably distorted as in H. titan. Many grains are 

 but partially gelatinized and others have been little 

 affected beyond the fissuration of the grains, but more 

 grains have advanced further in the process than in 

 H. titan. 



The reaction with sulphuric acid begins immediately. 

 Complete gelatinization occurs in about 20 per cent of 

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

 starch in 5 minutes; in about 67 per cent of the grains 

 and 88 per cent of the total starch in 15 minutes; 

 in about 92 per cent of the grains and 98 per cent of the 

 total starch in 30 minutes. (Chart D 26.) 



The reaction with hydrochloric acid begins imme- 

 diately. Complete gelatinization occurs in about 3 per 

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

 the total starch in 5 minutes; in about 22 per cent of 

 the grains and 48 per cent of the total starch in 15 

 minutes ; in about 40 per cent of the grains and 74 per 

 cent of the total starch in 30 minutes; in about 60 per 

 cent of the grains and 78 per cent of the total starch in 

 45 minutes; in about 65 per cent of the grains and 83 

 per cent of the total starch in 60 minutes. (Chart D 27.) 



The reaction with potassium hydroxide begins imme- 

 diately. Complete gelatinization occurs in about 13 per 

 cent of the grains and 19 per cent of the total starch in 

 5 minutes; in about 24 per cent of the grains and 48 per 

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

 cent of the grains and 58 per cent of the total starch in 

 30 minutes; in about 35 per cent of the grains and 63 

 per cent of the total starch in 45 minutes; in about 48 

 per cent of the grains and 65 per cent of the total starch 

 in (.0 minutes/ (Chart D28.) 



The reaction with potassium iodide begins in a few 

 grains in half a minute. Complete gelatinization occurs 



in about 1 per cent of the entire number of grains and 3 

 per cent of the total starch in 5 minutes ; in about 2 per 

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

 in 15 minutes; in about 5 per cent of the grains and 8 

 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 ; in about 9 per cent of the grains and 15 

 per cent of the total starch in 60 minutes. (Chart D 29.) 



The hilum swells slightly and occasional fissures 

 located here become enlarged and refractive, but less 

 prominent than in //. titan; no bubble is detected at the 

 hilum, as in H. titan. The entire grain becomes very 

 refractive, and the appearance of one lamella and of a 

 border of greater refractivity around the main body of the 

 grain are observed in 11. titan. New fissures are formed 

 of a similar character but not quite so deep as in H. titan. 

 The methods of gelatinization are varied as in H. titan, 

 but the process does not so frequently start at the distal 

 end ; it advances toward the proximal end, and in some 

 grains a pitted appearance precedes gelatinization. In 

 grains in which the border is very prominent a number of 

 fissures may form within this area, followed by the break- 

 ing into segments of the marginal lamella of the border 

 or of the lamella forming a demarcation between the 

 border and the main body of the grain. This method of 

 gelatinization is followed either by the slashing of the 

 capsule at various points or of its becoming considerably 

 distorted when these segments are present in the boun- 

 dary of the main body of the grain. The method of gela- 

 tinization just described was not observed in H. titan. 



The gelatinized grains are swollen and somewhat to 

 considerably more distorted than in II. titan so that 

 they do not resemble the untreated grain as in II. titan. 

 Many grains are but little affected and others have been 

 disorganized into granules but have not proceeded fur- 

 ther; fewer grains remain unaffected and more are dis- 

 organized than in H. titan. 



The reaction with potassium sulphocyanate begins in 

 a few grains in half a minute. Complete gelatinization 

 occurs in about 1 per cent of the entire number of grains 

 and 2 per cent of the total starch in 5 minutes ; in about 

 3 per cent of the grains and 8 per cent of the total starch 

 in 15 minutes ; in about 15 per cent of the grains and 22 

 per cent of the total starch in 30 minutes; in about 25 

 per cent of the grains and 54 per cent of the total starch 

 in 45 minutes ; in about 42 per cent of the grains and 60 

 per cent of the total starch in 60 minutes. (Chart D 30.) 



The hilum, as in II. titan, enlarges somewhat, but no 

 bubble is detected; the fissure in the untreated grain, if 

 present, becomes more prominent and extends more 

 widely, obliquely, transversely, or longitudinally. It 

 may either proceed from or intersect the hilum. If no 

 fissures are present in the untreated grain, new ones are 

 found, and these are usually longitudinal in direction and 

 often branched. The lamellae gradually become more 

 distinct than in //. titan, and, as a rule, remain so until 

 near the end of the reaction. Gelatinization begins in the 

 less-resistant grains as in those of //. titan, and proceeds 

 in the same manner; while in the more resistant grains, 

 of which there are more than in //. titan, gelatinization 

 begins at the distal end with considerable swelling and 

 distention of the capsule not noted in H. titan, but from 

 this point on the process is the same as in H. titan. 



