466 



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



variation in depth and tint than in C. zeylanicum. With 

 a 0.125 per cent Lugol's solution the grains color a quite 

 light blue-violet which deepens gradually, some being 

 lighter and bluer than others. After heating in water 

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

 cent Lugol's solution, the grains color a light to a moder- 

 ately deep blue, there being a little larger proportion of 

 the former, making the average depth of coloration con- 

 siderably less than in C. zeylanicum. The solution colors 

 a moderately deep indigo-blue, a little lighter than in 

 C. zeylanicum. If the preparation is boiled for 2 min- 

 utes, and then treated with an excess of a 2 per cent 

 Lugol's solution, the grain-residues become a light blue, 

 some with a reddish tint, lighter than in C. zeylanicum. 

 The capsules color a deep old-rose to wine-red, the major- 

 ity redder than in C. zeylanicum. 



Aniline Reactions. 



With gentian violet the grains color moderately light 

 immediately, somewhat lighter than in G. zeylanicum. 

 In half an hour they are colored moderate to deep, there 

 being a less number of grains of the latter color than in 

 C zeylanicum, hence the average reaction is lighter than 

 in the latter (value 60) . The body of the grain with rare 

 exceptions tends to color more deeply than the lustrous 

 border, this being the reverse of what was observed in 

 G. zeylanicum. There is less contrast between these 

 areas of the grain than noted in the latter. 



With safranin the grains stain lightly at once, some- 

 what lighter than in G. zeylanicum. In half an hour 

 they are colored moderately (value 60). The same ten- 

 dency is shown for the body of the grain to color more 

 deeply than the lustrous border, but somewhat more 

 markedly than with gentian violet. The differences in 

 the depth of color in the same aspect of a given grain 

 and the variations in the different grains are much less, 

 and the mean coloration of the grains is somewhat lighter, 

 than in C zeylanicum. 



Temperature Reactions. 

 The temperature of gelatinization of the majority of 

 the grains is 70° to 71° C, and of all 74° to 75° C, mean 

 74.5° C. 



Effects of Various Reagents. 



The reaction with chloral hydrate begins immediately. 

 Complete gelatinization occurs in about 39 per cent of 

 the entire number of grains and 46 per cent of the total 

 starch in 5 minutes; in about 50 per cent of the grains 

 and 57 per cent of the total starch in 15 minutes ; in about 

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

 starch in 30 minutes ; in about 63 per cent of the grains 

 and 68 per cent of the total starch in 45 minutes, with lit- 

 tle if any further change in 60 minutes. (Chart D 148.) 



Either a bubble appears at the hilum or the fissure 

 present becomes much enlarged and very refractive. The 

 bubble when present is less resistant and the enlarged 

 cleft is much less frequent in many grains than in G. 

 zeylanicum. The lamella? do not usually become more 

 distinct as in G. zeylanicum. A refractive border is 

 formed as in C. zeylanicum, but it is frequently broader 

 around the entire margin of the grain and a more bril- 

 liant lamella sometimes forms a line of demarcation be- 

 tween the main body of the grain and the border. Gela- 

 tinization usually begins at the distal margin or at the 



convex border (modified distal margin) of the plano- 

 convex grains, similar to that noted for C. zeylanicum; 

 but the process often spreads around the entire margin 

 before the region directly around the hilum is affected, 

 while it advances from both ends in other grains. These 

 methods were not observed in G. zeylanicum. The gela- 

 tinization process is accompanied by considerable disten- 

 tion and much ruffling of the capsule, much greater than 

 in C. zeylanicum. 



The gelatinized grains are swollen and much dis- 

 torted, the distortion of the entire margin is greater than 

 in C. zeylanicum. At the end of the reaction (60 min- 

 utes) a number of grains remain which are but little 

 affected, although a much less number than in C. zey- 

 lanicum. If the grains are partially gelatinized, the part 

 which remains unaffected is generally the proximal end 

 and the area surrounding the hilum ; the enlarged fissure 

 at this latter point remains very refractive as in G. 

 zeylanicum. 



The reaction with chromic acid begins in a few grains 

 in 1 minute. Complete gelatinization occurs in about 35 

 per cent of the entire number of grains and in about 45 

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

 same percentage of grains and in about 70 per cent of the 

 total starch in 15 minutes ; and in all grains but outlines 

 of portions of a few grains and in over 99 per cent of the 

 total starch in 30 minutes. (Chart D 149.) 



The reaction with pyrogallic acid begins immedi- 

 ately. Complete gelatinization occurs in about 50 per 

 cent of the total starch in 1 minute, in about 65 per cent 

 in 2 minutes, in about 85 per cent in 3 minutes, and 

 in all except traces of the margins of a few scattered 

 grains, making over 98 per cent of the total starch, in 

 5 minutes. (Chart D 150.) 



The reaction with nitric acid begins immediately. 

 Complete gelatinization occurs in about 50 per cent of 

 the entire number of grains and 75 per cent of the total 

 starch in 1 minute; in about 67 per cent of the grains 

 and 89 per cent of the total starch in 3 minutes ; in about 

 75 per cent of the grains and 92 per cent of the total 

 starch in 5 minutes ; in about 84 per cent of the grains 

 and 95 per cent of the total starch in 10 minutes; in 

 about the same number of grains and 96 per cent of the 

 total starch in 15 minutes; and in about 92 per cent of 

 the grains and over 99 per cent of the total starch in 30 

 minutes. At the end of 60 minutes a very small area 

 at the proximal end of very rare grains remains ungel- 

 atinized. 



The reaction proceeds rapidly through the mesial por- 

 tion of the grain to the distal margin, the proximal end 

 and sides in most grains proving the most resistant. 

 Exceptions occur when either a prolongation or protuber- 

 ance exists at the proximal end, which part is then gela- 

 tinized before the distal margin. A border located at 

 the convex margin of plano-convex grains may be the first 

 gelatinized ; the process then sometimes proceeding across 

 the plane surface before the area directly around the 

 hilum is disorganized. The mesial portion of the grain is 

 disorganized much more rapidly and with less refractive 

 granules than in C. zeylanicum, the distal margin is 

 generally more resistant, and the gelatinized grains have 

 the capsule intact instead of dissolving at the distal mar- 

 gin during the gelatinization of the granules as in G. 

 zeylanicum. The gelatinized grains are much swollen 



