502 



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



Polariscopic Properties. 

 The figure is nearly centric to very eccentric, some- 

 what more eccentric than in TV. bowdeni, the same as 

 in TV. sarniensis var. corusca major, and is distinct and 

 usually more clear-cut than in TV. bowdeni. The lines 

 are finer than in TV. bowdeni and TV. sarniensis var. 

 corusca major, and intersect obliquely as in TV. bowdeni. 

 They are less apt to be bent and bisected than in TV. 

 boivdeni, but much more than in TV. sarniensis var. 

 corusca major. A number of grains is noted which have 5 

 or 6 lines in the figure, but not so many as in TV. boivdeni. 

 The degree of polarization is moderately high to very 

 high (value 80), less than in either parent but closer 

 to TV. bowdeni. There are moderately high grains and 

 fewer very high grains than in TV. bowdeni. There is 

 comparatively little variation in polarization in the same 

 aspect of a given grain, as in TV. sarniensis var. corusca 

 major. 



With selenite the quadrants are usually well defined, 

 unequal in size, and less irregular in shape than in TV. 

 boivdeni, but considerably more than in TV. sarniensis var. 

 corusca major. The colors are more apt to be pure than 

 in TV. bowdeni, nearly as pure as in TV. sarniensis var. 

 corusca major, but there are a fewer grains having a 

 greenish tinge. 



In the character of the figure, the degree of polariza- 

 tion, and the appearances with selenite TV. giantess is 

 closer to TV. bowdeni than to TV. sarniensis var. corusca 

 major. 



Iodine Reactions. 

 With 0.25 per cent Lugol's solution the grains color a 

 moderate to deep blue-violet (value 60), the same as in 

 TV. sarniensis var. corusca major in depth, and as TV. 

 bowdeni in tint. With 0.125 per cent Lugol's solution 

 the grains color a light to moderate blue-violet, some- 

 what deeper than in TV. bowdeni, but less than in TV. sar- 

 niensis var. corusca major. After heating in water 

 until the grains are gelatinized, and then adding a 2 per 

 cent Lugol's solution, the grains color a very light 

 to a very deep indigo-blue, the mean deeper than in TV. 

 boivdeni, but less than in TV. sarniensis var. corusca major; 

 the capsules, of which some can be distinguished, color 

 violet as in TV. bowdeni; and the solution a deep indigo- 

 blue, somewhat less than in TV. bowdeni, but more than 

 in TV. sarniensis var. corusca major. If the preparation 

 is boiled for 2 minutes, and then treated with an excess 

 of 2 per cent Lugol's solution, the grain-residues color 

 a light to deep indigo with a tinge of red, somewhat 

 more than in TV. bowdeni, but distinctly less than in TV. 

 sarniensis var. corusca major; the capsules color a pinkish 

 violet as in TV. bowdeni; and the solution a very deep 

 indigo as in TV. boivdeni. 



Quantitatively and qualitatively the iodine reactions 

 of the unheated grains are closer to TV. sarniensis var. 

 corusca major than to TV. bowdeni, but quantitatively 

 and qualitatively in the grains that have been heated 

 they are closer to TV. bowdeni than to TV. sarniensis var. 

 corusca major. 



Aniline Reactions. 

 With gentian violet, the grains are stained, lightly at 

 once, and in half an hour they are moderately stained 

 (value 45), the same as in TV. bowdeni, and more than in 

 TV. sarniensis var. corusca major. 



With safranin the grains are stained, lightly at once, 

 and in half an hour they are moderately stained (value 

 50), the same as in TV. bowdeni, and much more than in 

 TV. sarniensis var. corusca major. 



The aniline reactions of these grains show a much 

 closer resemblance to TV. boivdeni than to TV. sarniensis 

 var. corusca major. 



Temperature Reactions. 



The majority of the grains are gelatinized at 68.2° 

 to 69.1° C, and all at 70.9° to 71° C, mean 70.95° C. 



The temperature of gelatinization of TV. giantess is 

 less than either parent and is closer to TV. bowdeni than to 

 TV. sarniensis var. corusca major. 



Effects of Various Reagents. 



The reaction with chloral hydrate begins immedi- 

 ately. Complete gelatinization occurs in about 10 per 

 cent of the entire number of grains and 17 per cent of 

 the total starch in 5 minutes; in about 75 per cent of 

 the grains and 80 per cent of the total starch in 15 min- 

 utes; in about 89 per cent of the grains and 95 per cent 

 of the total starch in 30 minutes ; in about 94 per cent of 

 the grains and 97 per cent of the total starch in 45 

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

 cent of the total starch in 60 minutes. (Chart D 211.) 



The hilum is as distinct as in TV. sarniensis var. 

 corusca major, but the lamellae are not as distinct as in 

 either parent. A broad refractive band, which is as re- 

 fractive as in TV. sarniensis var. corusca major, is formed 

 about the margins of the grains. Gelatinization usually 

 begins at the proximal end, and less often at the distal 

 end and progresses as in TV. bowdeni, but with less 

 Assuring. 



The gelatinized grains are larger and more distorted 

 than in TV. sarniensis var. corusca major, but not so much 

 as in TV. bowdeni. 



In this reaction TV. giantess shows qualitatively a 

 closer relationship to TV. bowdeni than to TV. sarniensis 

 var. corusca major. 



The reaction with chromic acid begins in rare grains 

 in 1 minute. Complete gelatinization occurs in much 

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

 total starch in 5 minutes; still in less than 0.5 per cent 

 of the grains and 2 per cent of the total starch in 15 

 minutes ; in about 14 per cent of the grains and 68 per 

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

 cent of the grains and 89 per cent of the total starch in 45 

 minutes ; in about 89 per cent of the grains and 98 per 

 cent of the total starch in 60 minutes. (Chart D 212.) 



The reaction with pyrogallic acid begins in rare 

 grains immediately. Complete gelatinization occurs in 

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

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

 grains and 1 per cent of the total starch in 15 minutes; 

 very little if any further advance in 30, 45, and 60 min- 

 utes, respectively. (Chart D 213.) 



The reaction with nitric acid begins immediately. 

 Complete gelatinization occurs in about 6 per cent of 

 the entire number of grains and 33 per cent of the total 

 starch in 5 minutes; in about 33 per cent of the grains 

 and 74 per cent of the total starch in 15 minutes ; in about 

 53 per cent of the grains and 88 per cent of the total 



