740 



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



region towards the proximal end being either not at all 

 or slightly distorted. The gelatinized grains do not 

 resemble the form of the untreated grains. 



The reaction with sodium salicylate begins imme- 

 diately. Complete gelatinization occurs in about 29 per 

 cent of the entire number of grains and 39 per cent of 

 the total starch in 5 minutes; in about 73 per cent of the 

 grains and 84 per cent of the total starch in 15 minutes; 

 in about 98 per cent of the grains and 99 per cent of the 

 total starch in 30 minutes. (Chart D 586.) 



The hilum is moderately distinct, and sometimes a 

 small bubble is formed there, and, just preceding the 

 beginning of gelatinization, there may be seen in some 

 grains 2 or 3 folds or wrinkles in the capsule extending 

 distally from the hilum nearly to the margin. The 

 lamella? are moderately distinct at first, but later become 

 indistinct. A broad, refractive band is quickly formed 

 about the margin of the grain before gelatinization be- 

 gins, and proceeds inward from the margin as gelatiniza- 

 tion progresses. Gelatinization, in the more quickly- 

 reacting grains, begins at the distal and then at the 

 proximal end, and from these points rapidly encircles the 

 whole margin, and this is followed by a rapid invasion 

 of the ungelatinized starch by cracks, small pieces are 

 broken off and gelatinized, and when the hilum is 

 reached the bubble, if present, swells, then shrinks, and 

 finally disappears, and the starch surrounding the hilum 

 becomes finely granular and then gelatinous. In the 

 more resistant grains, which are in the majority, gela- 

 tinization begins, usually, at the distal corners, from 

 which points it extends all along the distal margin, 

 and then to the proximal end, with sudden swelling of 

 the hilum, and with swelling, shrinkage, and disappear- 

 ance of the bubble if present. From these points, 

 gelatinization (preceded by a somewhat translucent 

 appearance) progresses smoothly, without Assuring or 

 granulation, to the more resistant portion of the grain, 

 of which the margin is the most resistant part and is 

 gelatinized after the central portion is gelatinized. The 

 gelatinized grains are much swollen and distorted and 

 show but little of the form of the untreated grain. 



The reaction with calcium nitrate begins immediately. 

 Complete gelatinization occurs in about 36 per cent of 

 the entire number of grains and 72 per cent of the total 

 starch in 5 minutes; in about 72 per cent of the grains 

 and 91 per cent of the total starch in 15 minutes; in 

 about 94 per cent of the grains and 99 per cent of the 

 total starch in 30 minutes. (Chart D 587.) 



The reaction with -uranium nitrate begins in a few 

 grains in 30 seconds. Complete gelatinization occurs in 

 about 28 per cent of the entire number of grains and 65 

 per cent of the total starch in 5 minutes; in about 60 

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

 in 15 minutes; in about 70 per cent of the grains and 

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

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

 starch in 45 minutes; in about the same percentage of 

 both grains and total starch in 60 minutes. (Chart D588.) 



The reaction with strontium nitrate begins imme- 

 diately. Complete gelatinization occurs in about 63 per 

 cent of the entire number of grains and 84 per cent of 

 the total starch in 2 minutes ; in about 90 per cent of the 

 grains and 95 per cent of the total starch in 5 minutes. 

 (Chart D 589.) 



The reaction with cobalt nitrate begins in a few grains 

 in 1 minute. 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 11 per cent 

 of the grains and 32 per cent of the total starch in 15 

 minutes; in about 28 per cent of the grains and 56 .per 

 cent of the total starch in 30 minutes; in about 28 per 

 cent of the grains and 69 per cent of the total starch in 

 45 minutes ; in about 34 per cent of the grains and 72 per 

 cent of total starch in 60 minutes. (Chart D 590.) 



The reaction with copper nitrate begins immediately. 

 Complete gelatinization occurs in about 64 per cent of 

 the entire number of grains and 96 per cent of the total 

 starch in 5 minutes; in about 87 per cent of the grains 

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

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

 the total starch in 15 minutes. (Chart D 591.) 



The reaction with cupric chloride begins in a few 

 grains in 30 seconds. Complete gelatinization occurs in 

 about 16 per cent of the grains and 51 per cent of the 

 total starch in 5 minutes; in about 32 per cent of the 

 grains and 76 per cent of the total starch in 15 minutes; 

 in about 49 per cent of the grains and 84 per cent of the 

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

 grains and S7 per cent of the total starch in 45 minutes ; 

 in about 68 per cent of the grains and 90 per cent of the 

 total starch in 60 minutes. (Chart D 592.) 



The reaction with barium chloride begins in a few 

 grains in 30 seconds. Complete gelatinization occurs in 

 rare grains, 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 grains and 2 per cent of the 

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

 grains and 3 per cent of the total starch in 30 minutes ; 

 little if any further advance in 45 and 60 minutes, respec- 

 tively. (Chart D 593.) 



The reaction with mercuric chloride begins imme- 

 diately. Complete gelatinization occurs in about 11 per 

 cent of the grains and 55 per cent of the total starch in 

 5 minutes ; in about 28 per cent of the grains and 74 per 

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

 cent of the grains and 83 per cent of the total starch in 

 30 minutes ; in about 52 per cent of the grains and 90 per 

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

 percentage of both the grains and total starch in 60 

 minutes. (Chart D 594.) 



Phaius wallichii (Pollen Parent). 



(Plate 23, fig. 139; Charts D 574 to D 594.) 

 Histologic Properties. 

 In form most of the grains are simple and isolated 

 with the exception of a few which appear in aggregates 

 of usually 2, rarely 3, components. Compound and semi- 

 compound grains of usually 2, rarely 3, components are 

 sometimes observed. The proportion of aggregates and 

 compound grains is greater than in P. grandifolius. 

 Well-defined pressure facets are not present, as was also 

 noted in P. grandifolius. The grains are frequently 

 irregular, much more often than in P. grandifolius, the 

 irregularities being of the same character, but given forms 

 of irregularity vary in frequency as follows : the nipple- 

 like excrescence or protuberance is less frequent; a 

 moderately large, rounded protuberance near the proxi- 



