518 



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



idly, and the outer row of granules persists for some time, 

 but finally disappears. In the second type 2 furrows 

 or actual fissures are formed running transversely or 

 obliquely from the hilum to the margin and the mate- 

 rial included between them and the hilum and the distal 

 margin, which comprises the greater part of the grain, 

 is divided into a fine granular mass in which the gran- 

 ules are arranged in rows corresponding to the lamellae, 

 which, as gelatinization and swelling begin, loses the 

 lamellar arrangement and is invaded at the margin 

 by many short, straight fissures. The material at the 

 proximal end meantime forms a distinctly striated 

 band at the proximal margin and sides nearby. Gela- 

 tinization proceeds more rapidly in the distal granular 

 mass from the hilum to the margin and is accompanied 

 by much swelling and considerable distortion of the 

 capsule. The proximal starch gelatinizes more slowly 

 and finally only a row of refractive granules remains at 

 the margin, which very slowly disappears. The third 

 type of gelatinization is the same as the first except that 

 there is no division into primary and secondary starch, 

 and therefore there is no formation of resistant particles 

 around the hilum. 



The gelatinized grains are much swollen, have mod- 

 erately thin capsules, and are somewhat distorted but re- 

 tain some resemblance to the form of the untreated 

 grain. Some grains show partial dissolution at one or 

 many places before gelatinization is complete. 



The reaction with sulphuric acid begins immediately. 

 Complete gelatinization occurs in about 71 per cent of 

 the entire number of grains and 93 per cent of the 

 total starch in 2 minutes; in about 97 per cent of the 

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

 in 5 minutes; in about 99 per cent of the grains and 

 more than 99 per cent of the total starch in 10 minutes. 

 (Chart D 264.) 



The hilum is distinct and a rather large bubble is 

 often present. The lamellae are moderately distinct in 

 some grains but not visible in the majority. Gelatiniza- 

 tion begins at the hilum and progresses according to two 

 methods. In the majority of the grains the starch im- 

 mediately surrounding the hilum is split into three or 

 four pieces and the bubble, if present, swells, then 

 shrinks, and disappears; the grains begins to swell and 

 the remainder of the substance is pushed to the margin 

 as a homogeneous-looking, refractive band, while the 

 three or four pieces of starch in the center of the grain 

 are converted into a mass of fine granules and soon gela- 

 tinized, the marginal band becomes thinner and more 

 refractive, and finally is gelatinized, leaving only the 

 capsule; in some grains a fissure is formed separating 

 the primary from the secondary starch, and the latter is 

 partially separated into concentric groups of lamellae, 

 which are later fused in the marginal band; from this 

 point inward the progress is similar to that already 

 described. In the second method 2 furrows or actual 

 fissures extend transversely, or sometimes obliquely, from 

 either side of the hilum nearly to the margin and the 

 material between them, the hilum and the margin is 

 transformed into a finely granular mass which often 

 shows somewhat of a lamellar arrangement. This is 

 quickly lost, however, and the whole melts down into a 

 gelatinous mass with much swelling. In the meantime 

 the more resistant material at the proximal end and sides 



nearby is pushed to the margin, where it forms a homo- 

 geneous-looking, rather refractive marginal band which 

 grows progressively thinner and more nearly transparent 

 until all the material composing it is gelatinized and only 

 the capsule is left. 



The gelatinized grains are much swollen and have 

 moderately thick capsules. They are considerably dis- 

 torted and do not bear much resemblance to the form of 

 the untreated grain. 



The reaction with hydrochloric acid begins imme- 

 diately. Complete gelatinization occurs in about 23 per 

 cent of the entire number of grains and 88 per cent of 

 the total starch in 5 minutes; in about 54 per cent of 

 the grains and 95 per cent of the total starch in 15 

 minutes; in about 70 per cent of the grains and 97 per 

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

 of the grains and 98 per cent of the total starch in 45 

 minutes ; in about 88 per cent of the grains and 99 per 

 cent of the total starch in 60 minutes. (Chart D 271.) 



The reaction witli potassium hydroxide begins im- 

 mediately. Complete gelatinization occurs in about 1 

 per cent of the entire number of grains and 19 per cent 

 of the total starch in 5 minutes; in about 13 per cent 

 of the grains and 36 per cent of the total starch in 15 

 minutes; in about 16 per cent of the grains and 43 per 

 cent of the total starch in 30 minutes; in about 23 per 

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

 45 minutes ; in about 25 per cent of the grains and 53 per 

 cent of the total starch in 60 minutes. ( Chart D 272. ) 



The reaction with potassium iodide begins in half a 

 minute. Complete gelatinization occurs in about 1 per 

 cent of the entire number of grains and 5 per cent of 

 the total starch in 5 minutes; in about 11 per cent of 

 the grains and 51 per cent of the total starch in 15 min- 

 utes ; in about 22 per cent of the grains and 68 per cent 

 of the total starch in 30 minutes ; in about 36 per cent of 

 the grains and 77 per cent of the total starch in 45 min- 

 utes ; in about 44 per cent of the grains and 80 per cent 

 of the total starch in 60 minutes. (Chart D 273.) 



The reaction with potassium sulphocyanate begins 

 immediately. Complete gelatinization occurs in about 

 8 per cent of the entire number of grains and 45 per cent 

 of the total starch in 5 minutes; in about 40 per cent 

 of the grains and 70 per cent of the total starch in 15 

 minutes ; in about 60 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 90 per cent of the total starch in 

 45 minutes; in 73 per cent of the grains and 97 per cent 

 of the total starch in So minutes. (Chart D 274.) 



The reaction with potassium sulphide begins in rare 

 grains in half a minute. Complete gelatinization was 

 not observed in any of the grains and gelatinization occurs 

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

 slight advance in 15 minutes; in less than 0.5 per cent of 

 the grains and 2 per cent of the total starch in 30 min- 

 utes; in about 1 per cent of the grains and 4 per cent of 

 the total starch in 45 minutes; in about the same of 

 both the grains and total starch in 60 minutes. (Chart 

 D275.) 



The reaction with sodium hydroxide begins imme- 

 diately. Complete gelatinization occurs in about 3 per 

 cent of the entire number of grains and 18 per cent of the 

 total starch in 5 minutes; in about 24 per cent of the 



