600 



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



scattered grains are quite resistant and may remain un- 

 gelatinized for 5 minutes or longer. 



The reaction with potassium sulphocyanate begins im- 

 mediately. Complete gelatinization occurs in about 80 

 per cent of the entire number of grains and 87 per cent 

 of the total starch in 15 seconds; in about 92 per cent of 

 the grains and 95 per cent of the total starch in 30 sec- 

 onds; and in about 97 per cent of the grains and in 

 more than 99 per cent of the total starch in 1 minute. 

 Bare scattered grains remain ungelatinized for 5 minutes 

 or longer. 



The reaction with potassium sulphide begins imme- 

 diately. Complete gelatinization occurs in more than 99 

 per cent of the entire number of grains and total starch 

 in 15 seconds. Very rare resistant grains remain for 5 

 minutes or longer. 



The reaction with sodium hydroxide begins imme- 

 diately. Complete gelatinization occurs, in all but rare 

 grains, in more than 99 per cent of the grains and total 

 starch in 15 seconds. Bare resistant grains remain un- 

 gelatinized for 5 minutes and longer. 



The reaction with sodium sulphide begins imme- 

 diately. Complete gelatinization occurs in about 90 per 

 cent of the entire number of grains and 98 per cent of 

 the total starch in 15 seconds; in about 96 per cent of the 

 grains and 99 per cent of the total starch in 30 seconds; 

 and in more than 99 per cent of the grains and total 

 starch in 45 seconds. Rare resistant grains remain un- 

 gelatinized for 5 minutes or longer. 



The reaction with sodium salicylate begins in 30 sec- 

 onds. Complete gelatinization occurs in about 28 per 

 cent of the entire number of grains and 53 per cent of 

 the total starch in 3 minutes; in about 71 per cent of the 

 grains and 84 per cent of the total starch in 5 minutes ; 

 and in about 97 per cent of the grains and 99 per cent of 

 the total starch in 10 minutes. (Chart D 352.) 



The reaction with calcium nitrate begins immedi- 

 ately. Complete gelatinization occurs in about 55 per 

 cent of the entire number of grains and 85 per cent of 

 the total starch in 1 minute ; in about 85 per cent of the 

 grains and 97 per cent of the total starch in 3 minutes; 

 and in about 97 per cent of the grains and 98 per cent 

 of the total starch in 5 minutes. 



The reaction with uranium nitrate begins in 30 sec- 

 onds. Complete gelatinization occurs in about 57 per 

 cent of the entire number of grains and 66 per cent 

 of the total starch in 1 minute, and in about 97 per cent 

 of the grains and 99 per cent of the total starch in 3 

 minutes. 



The reaction with strontium nitrate begins in 15 sec- 

 onds. Complete gelatinization occurs in about 57 per 

 cent of the entire number of grains and 73 per cent of 

 the total starch in 1 minute, and in about 98 per cent of 

 the grains and 99 per cent of the total starch in 3 minutes. 



The reaction with cobalt nitrate begins in a few 

 grains in 15 seconds. Complete gelatinization occurs in 

 about 4 per cent of the entire number of grains and 17 per 

 cent of the total starch in 1 minute ; in about 72 per cent 

 of the grains and 87 per cent of the total starch in 3 

 minutes; in about 82 per cent of the grains and 95 per 

 cent of the total starch in 5 minutes ; and in about 95 

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

 in 15 minutes. 



The hilum becomes distinct in all the grains, attended 

 by the formation of a bubble in a moderate number. The 

 lamellae are distinct. Gelatinization begins at the hilum, 

 which enlarges rapidly, especially toward the proximal 

 end, which is at first invaginated and later pushed out. 

 Two fissures extend obliquely from either side of the 

 hilum nearly to the distal margin and the deposit com- 

 prehended between them is first divided by fine longi- 

 tudinal and oblique fissures, which as the grain swells 

 separate it into spicules. As the grain continues to 

 swell this material is pushed to the distal end and it, 

 together with the portion at the distal margin, is 

 divided by wedge-shaped fissures into a serrated border. 

 Meanwhile, the starch at the proximal end and sides 

 forms a refractive marginal band which shows 2 or 3 faint 

 lamellar markings. It gradually loses this lamellated 

 appearance and becomes thinner and more nearly trans- 

 parent, until it is completely gelatinized and only the 

 capsule is left. The granular serrated material at the 

 distal end gradually grows more nearly transparent and 

 is finally gelatinized, with considerable distortion and 

 infolding of the capsule at this point. The gelatinized 

 grains are much swollen, have rather thin capsules, and 

 are very much distorted at the distal end and very little 

 distorted at the proximal end. 



The reaction with copper nitrate begins immediately. 

 Complete gelatinization occurs in about 55 per cent of 

 the entire number of grains and 75 per cent of the total 

 starch in 1 minute, and in about 97 per cent of the 

 grains and 99 per cent of the total starch in 3 minutes. 



The reaction with cupric chloride begins immediately. 

 Complete gelatinization occurs in about 55 per cent of 

 the entire number of grains and 77 per cent of the total 

 starch in 1 minute, and in about 94 per cent of the grains 

 and 99 per cent of the total starch in 3 minutes. 



The hilum becomes distinct in all the grains, attended 

 by the formation of a bubble in the majority of the grains. 

 The lamellae become distinct. Gelatinization begins at 

 the hilum, which swells more rapidly in the direction of 

 the proximal than the distal end. Two fissures extend 

 obliquely from either side of the hilum about one-half to 

 three-fourths of the distance between the hilum and the 

 distal margin. The material included between them is 

 first divided by very fine and rather indistinct fissures. 

 The portion just distal to the hilum is then divided into 

 spicules or bundles of spicules by a double row of fissures 

 which slant proximally from the 2 fissures proceeding 

 from either side of the hilum to the longitudinal axis of 

 the grain. These spicules are gelatinized first and leave 

 a residue of scattered refractive granules. The remainder 

 of the fissured portion is partially gelatinized, and as the 

 grain swells the rest of this part forms a small, irregu- 

 larly granular residue, at the distal end of the grain 

 which is usually gelatinized before the marginal portion 

 of the grain. The deposit at the proximal and distal 

 margins and sides forms a refractive, homogeneous-look- 

 ing band which is rather thick at first and gradually 

 grows thinner and more nearly transparent until it is 

 completely gelatinized, leaving only the capsule. The 

 gelatinized grains are very much swollen, have rather 

 thick capsules, and are somewhat distorted, particularly 

 at the distal end. 



The reaction with barium chloride begins in a few 

 grains in 30 seconds. Complete gelatinization occurs in 



