528 



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



in size. The colors are usually not pure. There are a 

 few grains which show a greenish tinge. 



Comparison of the polariscopic properties of N. 

 poeticus ornatus and N. tazetta grand monarque shows: 



The figure is no more distinct or clear-cut than in 

 N. tazetta grand monarque. The lines cross at an acute 

 angle of less variable size, and are somewhat less often 

 bent or bisected. The figure sometimes has the form of 

 an hyperbola. 



The degree of polarization is the same (value 50), 

 with the same amount of variation between the different 

 grains and in the same aspect of a given grain. 



With selenite the quadrants are less poorly defined 

 and somewhat less irregular in shape. The colors are 

 as often not pure as in N. tazetta grand monarque. 



IODINE REACTIONS. 



With 0.25 per cent of LugoPs solution, the grains 

 color a light to moderate violet tinged with blue (value 

 45), which deepens with moderate rapidity until the 

 grains are very deeply colored, becoming at the same time 

 bluer in tint. With 0.125 per cent Lugol's solution the 

 grains color a light violet, which deepens with moderate 

 rapidity until the grains are deeply colored, and at the 

 same time have assumed a blue tint. After heating in 

 water until the grains are gelatinized and then adding 

 2 per cent Lugol's solution, the gelatinized grains color a 

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

 tion a moderately deep indigo-blue. If the preparation 

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

 of 2 per cent of Lugol's solution most of the grain- 

 residues are colored a moderate indigo, some a light 

 indigo. The capsules are colored reddish violet, and the 

 solution a very deep indigo-blue. 



Comparison of the iodine reactions of N. poeticus 

 ornatus and 2V. tazetta grand monarque shows : 



The grains are colored less with 0.25 (value 40) and 

 0.125 Lugol's solution. After heating in water until 

 the grains are all gelatinized and then adding a 2 per 

 cent Lugol's solution more of the grains are moderately 

 deeply colored and the solution is less deeply colored 

 than in 2V. tazetta grand monarque. After boiling for 2 

 minutes, more of the grains are moderately colored and 

 the solution less deeply than in 2V. tazetla grand 

 monarque. 



ANILINE REACTIONS. 



With gentian violet the grains all stain very lightly 

 at once, and in half an hour they are light to moderately 

 colored (value 40). There is no variation in depth in 

 the different grains, and there is often some variation in 

 different parts of an individual grain. 



With safranin the grains all stain very lightly at 

 once, and in half an hour they are moderately colored 

 (value 45), somewhat more than with gentian violet. 

 There is often some variation in different parts of an 

 individual grain. 



Comparison of 2V. poeticus ornatus and 2V. tazetta 

 grand monarque shows : 



ANILINE REACTIONS. 



With gentian violet the grains all color somewhat 

 less (value 35) than in 2V. tazetta grand monarque, and 

 there is no variation in color in the individual "rains. 



With safranin the grains all color the same as in 2V. 

 tazetta grand monarque (value 45) and there is no varia- 

 tion in color in the individual grains. 



TEMPERATURE REACTIONS. 



The temperature of gelatinization of the majority of 

 the grains is 73 to 75 C., and of all 76 to 77 C., 

 mean 76.5 C. 



Comparison of the temperature of gelatinization of 

 2V. poeticus ornatus and 2V. tazetta grand monarque 

 shows : 



Mean 77.5 C. is somewhat higher (1) than in 

 2V. tazetta grand monarque. 



EFFECTS OF VARIOUS REAGENTS. 



The reaction with chloral hydrate begins in 1 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 16 per cent of the grains 

 and 24 per cent of the total starch in 15 minutes; in 

 about 28 per cent of the grains and 32 per cent of the 

 total starch in 30 minutes; in about 32 per cent of the 

 grains and 36 per cent of the total starch in 45 minutes; 

 in about 34 per cent of the grains and 40 per cent of the 

 total starch in 60 minutes. (Chart D265.) 



The hilum is not distinct in a few grains, and in the 

 great majority a small bubble is formed there, which 

 remains until the reaction is nearly completed. The 

 lamellae are not visible at first, but later become indis- 

 tinctly visible in most of the grains. The grains become 

 more refractive in appearance after the reagent is added 

 and the first part to show this increased refractivity is a 

 narrow band of starch at the margin. Gelatinization 

 begins at various discrete points on the distal margin or 

 at the ends of protuberances, wherever they are located. 

 In the less resistant grains gelatinization advances with 

 moderate rapidity from the initial points, with some 

 preliminary fissuring of the ungelatinized starch; when 

 near the hilum the bubble swells, then shrinks and 

 disappears and the hilum swells suddenly, and the 

 proximal starch, which is the most resistant part of 

 the grain is rapidly gelatinized. In the more resistant 

 grains, the margin at the distal end is gelatinized and 

 this is followed by a serial separation and gelatinization 

 of several distal groups of lamellre. The rest of the 

 grain is then invaded by fissures, and small particles are 

 broken off which gelatinize separately. When gelatiniza- 

 tion is near the hilum the bubble swells, then shrinks 

 and finally disappears, and the hilum swells rapidly. 

 The proximal starch, which is the last part of the grain 

 ungelatinized, rapidly assumes a more refractive appear- 

 ance and is then gelatinized. In the lenticular-shaped 

 grains a third method is noted. A broad refractive fis- 

 sure is seen in the long axis of the grain, and gelatiniza- 

 tion begins at the margin at either end of this and 

 advances smoothly, until the hilum, which is centric, is 

 reached. The hilum swells rapidly and the material 

 immediately surrounding it is quickly gelatinized. 



The gelatinized grains are much swollen and have 

 rather thick capsules. They are much distorted and do 

 not retain much resemblance to the form of the untreated 

 grain. 



Comparison of chloral hydrate reactions of 2V. poeti- 

 cus ornatus with 2V. tazett'a grand monarque shows: 



