590 



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



than N. triandrus albus. The fissures have the follow- 

 ing forms: (1) T, Y, and cruciate figures; (2) a single 

 straight, transverse, oblique, or longitudinal line; (3) 

 an irregularly stellate collection of fissures. The hilum 

 is sometimes centric, but in the majority of the grains it 

 is eccentric from 0.44 to 0.2, usually 0.33, of the longi- 

 tudinal axis. 



In the character of the hilum N. agues harvey shows 

 a closer relationship to N. leedsii minnie hume .than to 

 N. triandrus albus. The eccentricity of the hilum in 

 the three starches is so nearly the same that there is no 

 differentiation. 



The lamella; are as often distinct as in N. leedsii min- 

 nie hume, and more distinct than in N. triandrus albus. 

 They are as fine as in N. leedsii minnie hume and have 

 the same arrangement as in that starch. The number 

 counted on some of the larger grains varies from 6 to 

 16, usually 12. In the character of the lamella? N. agues 

 harvey shows a closer relationship to N. leedsii hume 

 than to N. triandrus albus. 



In size the grains vary from the smaller which are 

 3 by 3/i, to the larger broad forms which are 40 by 

 40^ and 36 by 40/x, and the larger elongated forms which 

 are 40 by 34/*, in length and breadth. The common 

 sizes are 22 by 18/*, 24 by 24/*, and 22 by 24/i in length 

 and breadth. In size the grains of N. agues harvey shows 

 a closer relationship to N. triandrus albus than to N. 

 leedsii minnie hume. 



Polariscopic Properties. 



The figure as in N. leedsii minnie hume is usually 

 moderately distinct and well defined. The lines cross at 

 an acute angle which does not vary greatly in size in the 

 different grains, and are frequently bent and sometimes 

 bisected, more often than in N. triandrus albus but as 

 often as in N. leedsii minnie hume. There are as often 

 5 or 6 lines instead of 4, and the figure as often has the 

 form of a conjugate hyperbola, or a long line bisected 

 at both ends, as in N. leedsii minnie hume. 



The degree of polarization varies from low to high 

 (value 45), the same as in N. leedsii minnie hume. 

 There is the same amount of variation in a given aspect 

 of an individual grain as in that starch. 



With selenite the quadrants, as in N. leedsii minnie 

 hume, are moderately clear-cut, unequal in size, and often 

 irregular in shape. The colors are as often impure and 

 as often have a greenish tinge as in that starch. 



In the degree of polarization, the character of the 

 figure, and the appearances with selenite, N. agues harvey 

 shows a closer relationship to N. leedsii minnie hume 

 than to N. triandrus albus. 



Iodine Reactions. 

 With 0.25 per cent Lugol's solution the grains all 

 color a moderate to deep violet tinged with blue (value 

 60), the same as in N. leedsii minnie hume. With 0.125 

 per cent Lugol's solution, they all color a light to moder- 

 ate violet, the same as in N. leedsii minnie hume. After 

 heating in water until the grains are all gelatinized, and 

 then treating with a 2 per cent Lugol's solution, the 

 gelatinized grains, as in N. leedsii minnie Mime, all color 

 a moderate to moderately deep indigo-blue, and the solu- 

 tion a moderate indigo-blue. If the preparation is boiled 

 for 2 minutes and then treated with a 2 per cent Lugol's 



solution, the grain-residues, as in N. leedsii minnie hume, 

 all color a light to moderate or moderate indigo-blue, the 

 capsules a reddish violet, and the solution an indigo- 

 blue. Qualitatively and quantitatively the reaction with 

 iodine shows a closer relationship to N. leedsii minnie 

 hume than to N. triandrus albus. 



Aniline Reactions. 



With gentian violet the grains all color very lightly 

 at once, and in 30 minutes they are light to moderately 

 colored (value 38), the same as in N. leedsii minnie 

 hume. 



With safranin the grains all color very lightly at once, 

 and in 30 minutes they are light to moderately colored 

 (value 40), the same as in both parents. 



In the reactions with aniline stains N. agues harvey 

 shows a somewhat closer relationship to N. leedsii minnie 

 hume than to N. triandrus albus. There are, however, no 

 marked differences between either of the parents or the 

 hybrid in these reactions. 



Temperature Reactions. 



The temperature of gelatinization of the majority of 

 the grains is 70° to 71.8° C, and of all is 73.8° to 

 75° C, mean 74.4° C. 



The temperature of gelatinization of N. agues harvey 

 is somewhat closer to that of N. triandrus albus than 

 N. leedsii minnie hume, though the temperatures of 

 gelatinization of the three starches are very close to one 

 another. 



Effects of Various Reagents. 



The reaction with chloral hydrate begins in 1 min- 

 ute. Complete gelatinization occurs in about 2 per cent 

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

 total starch in 5 minutes; in about 3 per cent of the 

 grains and 7 per cent of the total starch in 15 minutes; 

 in about 6 per cent of the grains and 8 per cent of the 

 total starch in 30 minutes; in about 8 per cent of the 

 grains and 12 per cent of the total starch in 45 minutes; 

 and in about 9 per cent of the grains and 14 per cent of 

 the total starch in 60 minutes. (Chart D 335.) 



The hilum becomes distinct, accompanied by the for- 

 mation of a bubble in as few grains as in N. leedsii minnie 

 hume. The lamella? are moderately distinct in a smaller 

 number of grains than in N. leedsii minnie hume, and 

 are not visible in the others as in all the grains of N. 

 triandrus albus. After the addition of the reagent the 

 grains become as refractive as in N. triandrus albus and 

 more refractive than in N. leedsii minnie hume. Gelati- 

 nization begins at the distal margin and progresses 

 according to the two methods described under both 

 parents. In the first, which is seen in a larger majority 

 of the grains than in N. leedsii minnie hume and a much 

 larger majority than in N. triandrus albus, it progresses 

 according to the method described under N. leedsii min- 

 nie hume, except that there is considerable Assuring and 

 breaking off of particles from the ungelatinized material. 

 This is not seen in either parent. In the second method, 

 which is noted in rather few of the grains, gelatinization 

 progresses from both ends as in both parents, or from 

 the distal end only as in N. triandrus albus. The gela- 

 tinized grains are as much swollen, have as thick cap- 

 sules, and are as much distorted as in N. leedsii minnie 

 hume. 



