708 



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



her of the grains are lightly colored, a few very lightly, 

 a few moderately, and some grains deeply. 



With safranin the grains all color lightly at once, and 

 in 30 minutes they are moderately to deeply colored 

 (value 50), 5 units less than in B. socotrana and 10 

 units less than in B. double light rose. The majority of 

 the grains are colored moderately, a few moderately to 

 lightly, and a few deeply. 



In the reactions with aniline stains B. ensign shows 

 a closer relationship to B. socotrana than to B. double 

 light rose. 



TEMPERATURE REACTIONS. 



The temperature of gelatinization of the majority of 

 the grains is 64 to 65.5 C., and of all 66 to 68 C., 

 mean 67 C. The mean is 4 C. higher than in B. double 

 light rose and 14.4 C. lower than in B. socotrana. 



EFFECTS OF VARIOUS REAGENTS. 



The reaction with chloral hydrate begins immedi- 

 ately. Complete gelatinization occurs in about 75 per 

 cent of the entire number of grains and 89 per cent of 

 the total starch in 5 minutes; in about 98 per cent 

 of the grains and 99 per cent of the total starch in 10 

 minutes. ( Chart D 527.) 



The hilum is indistinct as in B. double light rose. 

 The lamellae are invisible as in both parents. The grains 

 become somewhat more refractive after the addition of 

 the reagent and the first part of the grain to be so affected 

 is a narrow band at the margin which is as refractive as in 

 B. double light rose. Gelatinization begins at the distal 

 margin and proceeds as in B. double light rose except that 

 in no case is gelatinization preceded by a pitted appear- 

 ance of the ungelatinized starch, in this respect resem- 

 bling B. socotrana. The gelatinized grains are as much 

 swollen and have nearly as thick capsules as in B. double 

 light rose, and are nearly as much distorted as in B. soco- 

 trana. In this reaction B. ensign shows qualitatively a 

 somewhat closer relationship to B. double light rose than 

 to B. socotrana. 



The reaction with chromic acid begins immediately. 

 Complete gelatinization occurs in about 12 per cent of 

 the entire number of grains and 50 per cent of the 

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

 grains and 88 per cent of the total starch in 15 minutes ; 

 in about 63 per cent of the grains and 98 per cent of 

 the total starch in 30 minutes. (Chart D 528.) (See 

 pages 697 and 705.) 



The hilum and lamellae are as distinct as in B. soco- 

 trana. Gelatinization begins at the hilum as in both 

 parents, but progresses as in B. double light rose, except 

 that the inner mass of starch remains less gelatinized 

 and more granular before solution, showing the influence 

 of B. socotrana. 



The reaction with pyrogallic add 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 12 per cent of the total starch in 5 minutes ; in about 

 5 per cent of the grains and 30 per cent of the total starch 

 in 15 minutes; in about 33 per cent of the grains and 

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

 35 per cent of the grains and 65 per cent of the total 

 starch in 45 minutes ; in about 47 per cent of the grains 

 and 71 per cent of the total starch in 60 minutes. (Chart 

 D529.) 



The hilum and lamellse are as distinct as in B. soco- 

 trana. Gelatinization begins at the hilum and pro- 

 gresses as in B. double light rose, except that in some 

 grains an indistinct double row of slanting fissures may 

 be seen just distal to the hilum, showing the influence of 

 B. socotrana. The gelatinized grains are as much swol- 

 len, have somewhat thicker capsules (if they ever become 

 completely gelatinized, which is to be doubted in many 

 grains), and are not so much distorted as in that starch. 



In this reaction B. ensign shows qualitatively a closer 

 relationship to B. double light rose than to B. socotrana. 

 (See note, page 698.) 



The reaction with nitric acid begins immediately. 

 Complete gelatinization occurs in about 80 per cent of 

 the entire number of grains and 88 per cent of the 

 total starch in 15 seconds; in more than 99 per cent 

 of the grains and total starch in 30 seconds. (Chart 

 D531.) 



The hilum, as in B. double light rose, becomes dis- 

 tinct in all the grains, attended by the formation of a 

 bubble in a majority. The lamella? are as distinct as in 

 B. socotrana. Gelatinization begins at the hilum and 

 progresses as in B. dfluble light rose. The gelatinized 

 grains are as much swollen as in B. double light rose, 

 but the capsules are not so thick, and they are more 

 distorted at the distal end than in that starch. In this 

 reaction B. ensign shows qualitatively a closer relation- 

 ship to B. double light rose than to B. socotrana. 



The reaction with strontium nitrate begins imme- 

 diately. Complete gelatinization occurs in about 10 per 

 cent of the entire number of grains and 26 per cent of 

 the total starch in 1 minute; in about 78 per cent of the 

 grains and 91 per cent of the total starch in 2 minutes; 

 in about 95 per cent of the grains and 99 per cent of the 

 total starch in 3 minutes. (Chart D 532.) 



The hilum and lamella? are as distinct as in B. soco- 

 trana. Gelatinization begins at the hilum and pro- 

 ceeds as in B. double light rose, except that 2 fissures 

 proceeding from either side of the hilum are formed in 

 more grains than in that starch, and in some grains a 

 double row of rather indistinct slanting fissures is 

 formed as in B. socotrana. The gelatinized grains are 

 as much swollen, have as thick capsules, and are as much 

 distorted as in B. double light rose. In this reaction 

 B. ensign shows qualitatively a closer relationship to 

 B. double light rose than to B. socotrana. 



38. STARCHES OF BEGONIA DOUBLE WHITE, B. 



SOCOTKANA, AND B. JULIUS. 



Starch of Begonia socotrana (pollen parent) is de- 

 scribed on pages 704 to 707. 



BEGONIA DOUBLE WHITE (SEED PARENT) . 



(Plate 22, fig. 127; Charts D 533 to D 538.) 



HISTOLOGIC PROPERTIES. 



In form the grains are almost solely simple and iso- 

 lated, only occasionally compound grains and aggregates 

 are seen. The compound grains are always of one type : 

 2 small grains, each consisting of a hilum and 1 or 2 

 lamellae, surrounded by 30 or more secondary lamellae 

 and located at the proximal end of a large elongated 

 grain. The aggregates consist of 2, 3, or 4 small grains 

 or of 2 small grains adhering to the distal end of a 

 somewhat larger one. The grains are usually regular, 



