IRIS. 



643 



in about 6 per cent of the grains and 23 per cent of the 

 total starch in 60 minutes. (Chart D 388.) 



The reaction with sodium hydroxide begins imme- 

 diately. Complete gelatinization occurs in about 36 per 

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

 the total starch in 2 minutes; in about 63 per cent of 

 the grains and 87 per cent of the total starch in 5 min- 

 utes; in about 75 per cent of the grains and 91 per cent 

 of the total starch in 15 minutes; in about 83 per cent 

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

 minutes; in about 88 per cent of the grains and 97 per 

 cent of the total starch in 45 minutes; little if any 

 advance in 60 minutes. (Chart D 389.) 



The hilum is more distinct than in /. iberica, and the 

 2 refractive fissures which are usually present in the 

 untreated grain, become wider, more prominent, and 

 more branched, than in /. iberica. The lamellje are more 

 distinct than in /. iberica and remain visible for a longer 

 time. Gelatinization begins at the hilum as in /. iberica, 

 and the refractive fissures already described become much 

 wider and much more branched toward the distal end, 

 and a third very distinct, straight, longitudinal fissure 

 extends down the center of the grain from the hilum to 

 the distal margin. As gelatinization proceeds and the 

 hilum enlarges, this central fissure disappears and the 

 portion of the grain included between the 2 refractive, 

 marginal fissures, the hilum and the distal margin is 

 broken up into refractive granules which are arranged 

 in rows corresponding to the lamellar arrangement. 

 Gelatinization usually begins at the hilum and proceeds 

 toward the distal end, without the division of the grain 

 into pyramidal portions by fissures as in /. iberica, and 

 the distal starch rarely begins to be gelatinized at the 

 same time that the hilum begins as in /. iberica. The 

 most resistant part of the grain is in most of the grains 

 at the proximal end and sides nearby as in I. iberica, and 

 this portion, as the hilum and the grain swell, forms a 

 lamellated, striated band at the margin, which becomes 

 progressively thinner and more nearly transparent until 

 only the thin capsule is left. In a moderately large 

 minority, however, this part of the grain seems the least 

 resistant, and is gelatinized before all of the distal 

 material. The gelatinized grains are swollen, and have 

 somewhat thicker capsules and are more distorted than 

 in /. iberica. 



The reaction with sodium sulphide begins in a few 

 grains immediately. Complete gelatinization occurs in 

 about 10 per cent of the entire number of grains and 

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

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

 starch in 15 minutes; in about 39 per cent of the grains 

 and 67 per cent of the total starch in 30 minutes; in 

 about 39 per cent of the grains and 72 per cent of the 

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

 grains and 77 per cent of the total starch in 60 minutes. 

 (Chart D390.) 



The reaction with sodium salicylate begins imme- 

 diately. Complete gelatinization occurs in about 70 per 

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

 the total starch in 5 minutes ; in more than 99 per cent 

 of the grains and total starch in 10 minutes. (Chart 

 D391.) 



The hilum is as distinct as in I. iberica, but a bubble 

 is not nearly so frequently formed there as in that 



starch. The lamellae are at first indistinct, but later 

 become more distinct than in /. iberica. The grains, as in 

 /. iberica, become more refractive in appearance after the 

 addition of the reagent, and the first indication of this 

 change is the appearance of a moderately narrow, refrac- 

 tive band about the margin, which is not so narrow and 

 is more refractive than in /. iberica. Gelatinizatiou is not 

 always preceded by a pitted appearance of the distal end 

 of the grain, but begins at the corners of the distal 

 margin as in /. iberica. The progress of gelatinization 

 is very similar to that already described under /. iberica, 

 except that the grain is not so apt to become granular 

 in appearance just preceding gelatinizatiou, and the 

 process is much smoother. In many less grains than in 

 /. iberica are 2 longitudinal fissures observed, extending 

 from the distal margin toward the hilum, and there are 

 many more grains than in 7. iberica in which the proxi- 

 mal end is gelatinized when gelatinization has progressed 

 halfway from the distal margin to the hilum. 



The gelatinized grains are much swollen, have thicker 

 capsules, and are somewhat less distorted than in /. 

 iberica. 



The reaction with calcium nitrate begins in a few 

 grains immediately. Complete gelatinization occurs in 

 about 1 per cent of the entire number of grains and 7 

 per cent of the total starch in 5 minutes; in about 25 

 per cent of the grains and 66 per cent of the total starch 

 in 15 minutes ; in about 34 per cent of the grains and 

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

 39 per cent of the grains and 75 per cent of the total 

 starch in 45 minutes ; in about 50 per cent of the grains 

 and 79 per cent of the total starch in 60 minutes. (Chart 

 D392.) 



The reaction with uranium nitrate begins in a few 

 grains in 30 seconds. Complete gelatinization occurs in 

 less than 0.5 per cent of the entire number of grains 

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

 5 per cent of the grains and 25 per cent of the total 

 starch in 15 minutes ; in about 10 per cent of the grains 

 and 32 per cent of the total starch in 30 minutes; in 

 about 14 per cent of the grains and 40 per cent of the 

 total starch in 45 minutes; in about 16 per cent of the 

 grains and 45 per cent of the total starch in 60 minutes. 

 (Chart D393.) 



The reaction with strontium nitrate begins in a few 

 grains immediately. Complete gelatinization occurs in 

 about 2 per cent of the entire number of grains and 

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

 28 per cent of the grains and 69 per cent of the total 

 starch in 15 minutes; in about 47 per cent of the grains 

 and 80 per cent of the total starch in 30 minutes; in 

 about 68 per cent of the grains and 86 per cent of the 

 total starch in 45 minutes ; in about the same percentage 

 of the grains and 88 per cent of the total starch in 

 60 minutes. (Chart D 394.) 



The reaction with cobalt nitrate begins in a few 

 grains in 1 minute. Complete gelatinization occurs in 

 less than 0.5 per cent of the entire number of grains and 

 1 per cent of the total starch in 5 minutes ; in about 0.5 

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

 the total starch in 15 minutes; in about the same per- 

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

 in 30 minutes ; in about 1 per cent of the grains and 9 



