690 



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



The reaction with sulphuric acid begins immediately. 

 Complete gelatinization occurs in about 78 per cent of 

 the entire number of grains and 95 per cent of the total 

 starch in 5 minutes; in about 92 per cent of the grains 

 and 99 per cent of the total starch in 10 minutes; in 

 about 96 per cent of the grains and over 99 per cent of 

 the total starch in 15 minutes. (Chart D 488.) 



The reaction with hydrochloric acid begins imme- 

 diately. Complete gelatinization occurs in about 32 per 

 cent of the entire number of grains and 51 per cent of 

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

 the grains and 73 per cent of the total starch in 15 

 minutes ; in about 62 per cent of the grains and 86 per 

 cent of the total starch in 30 minutes; in about 69 per 

 cent of the grains and 90 per cent of the total starch in 

 45 minutes ; in about 73 per cent of the grains and 92 

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

 D489.) 



The hilum becomes distinct as in T. pottsii, and 

 two canals or fissures extend from the hilum to the distal 

 corners of the pressure facets when these are present. 

 The lamellae become visible, especially toward the distal 

 end, but are not distinct. Gelatinization begins at the 

 hilum, and fine stria? radiate from the hilum to the 

 margin as in T. pottsii, but, differing from the process in 

 that starch, the space between the hilum and the distal 

 end becomes invaded by coarse irregular fissures and 

 broken up into coarse granules, and these begin to gela- 

 tinize ; then as the hilum enlarges a number of irregular 

 fissures invade the remainder of the starch at the sides 

 and at the proximal end. The inner portion thus in- 

 vaded soon gelatinizes, leaving some scattered granules, 

 and a striated lamellated marginal band is formed ; this 

 band and the granules in the interior are more distinct 

 than in T. pottsii. Before gelatinization is complete the 

 margin is dissolved in one or more places, and granules 

 are broken off the uugelatinized portion and float away, 

 until all the material is dissolved. There are few if any 

 completely gelatinized grains, which is different from 

 T. pottsii. 



The reaction with potassium hydroxide begins imme- 

 diately. Complete gelatinization occurs in about 0.5 

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

 the total starch in 5 minutes ; in about 1 per cent of the 

 grains and 5 per cent of the total starch in 15 minutes; 

 in about 3 per cent of the grains and 9 per cent of the 

 total starch in 30 minutes; in about 5 per cent of the 

 grains and 14 per cent of the total starch in 45 minutes ; 

 in about 7 per cent of the grains and 20 per cent of the 

 total starch in 60 minutes. (Chart D 490.) 



The reaction with potassium iodide begins imme- 

 diately. Complete gelatinization occurs in about 2 per 

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

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

 entire number of grains and 12 per cent of the total 

 starch in 15 minutes; in about 11 per cent of the entire 

 number of grains and 18 per cent of the total starch 

 in 30 minutes; in about 16 per cent of the grains and 

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

 20 per cent of the grains and 27 per cent of the total 

 starch in 60 minutes. (Chart D491.) 



The hilum becomes more distinct than in T. pottsii, 

 and the lamella are visible but not very distinct. Gela- 

 tinization begins at the hilum as in T. pottsii, but 



never at the hilum and the margin simultaneously as in 

 that species, but the process of gelatinization is the same 

 except that the strias radiating from the hilum are more 

 distinct than in T. pottsii, and there is a smaller number 

 of quickly reacting grains, very few reaching the point 

 of complete gelatinization. The gelatinized grains are 

 swollen and somewhat distorted, but retain more of the 

 form of the untreated grain than do those of T. pottsii. 



The reaction with potassium sulphocyanate begins 

 immediately. Complete gelatinization occurs in about 11 

 per cent of the entire number of grains and 33 per cent 

 of the total starch in 5 minutes; in about 16 per cent 

 of the grains and 57 per cent of the total starch in 15 

 minutes ; in about 40 per cent of the grains and 75 per 

 cent of the total starch in 30 minutes; in about 53 per 

 cent of the grains and 82 per cent of the total starch in 

 45 minutes; in about 58 per cent of the grains and 86 

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

 D492.) 



The reaction with potassium sulphide begins in a 

 few grains in half a minute. Complete gelatinization 

 was not observed in any of the grains and in 0.5 per cent 

 of the total starch in 5 minutes; complete gelatinization 

 is observed in but rare grains, less than 0.5 per cent of 

 the entire number, and 1 per cent of the total starch in 

 15 minutes; slight advance in the total starch in 30 

 minutes ; still in less than 0.5 per cent of the grains and 

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

 same in 60 minutes. (Chart D 493.) 



The reaction with sodium hydroxide begins imme- 

 diately. Complete gelatinization occurs in about 6 per 

 cent of the grains and 16 per cent of the total starch 

 in 5 minutes ; in about 10 per cent of the grains and 33 

 per cent of the total starch in 15 minutes; in about 20 

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

 in 30 minutes; in about 26 per cent of the grains and 

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

 30 per cent of the grains and 58 per cent of the total 

 starch in 60 minutes. (Chart D 494.) 



The hilum becomes still more distinct than in T. 

 pottsii, and in some of the grains with pressure facets 

 on the margin 2 fissures leading from the hilum to the 

 corners of these pressure facets are observed. The 

 lamellffi, unlike those of T. pottsii, become distinct. 

 Gelatinization begins at the hilum, and in many less 

 grains than in T. pottsii at the margin and at the hilum 

 simultaneously. The progress of gelatinization is essen- 

 tially the same as in T. pottsii, except that the granules 

 formed near the hilum are larger and more numerous, 

 and the spicules into which the remaining starch is 

 broken are not so fine as in that starch. 



The gelatinized grains are considerably swollen and 

 somewhat distorted, but retain much of the form of the 

 untreated grain. There is no difference noted between 

 this starch and that of T. pottsii in this respect. 



The reaction with sodium sulphide begins imme- 

 diately. 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 4 per cent of the 

 grains and 13 per cent of the total starch in 15 minutes; 

 in about 11 per cent of the grains and 22 per cent of the 

 total starch in 30 minutes; in about 18 per cent of the 

 grains and 27 per cent of the total starch in 45 minutes; 



