IRIS. 



Ill 



of compound grains than in either parent; irregularity 

 is intermediate; and, on the whole, the resemblances 

 are distinctly closer to /. persica var. purpurea. The 

 hilum in character is closer to I. persica var. purpurea, 

 but in eccentricity closer to 7. sindjarensis. The lamellae 

 in character and number are closer to I. persica var. 

 purpurea. The size is closer to I. sindjarensis. In 

 the polariscopic and selenite reactions the relationship is 

 closer to /. persica var. purpurea, but in the qualitative 

 iodine reactions closer to I. sindjarensis. In the quali- 

 tative reactions with the chemical reagents the leanings 

 to one or the other parent are numerous and marked, 

 but on the whole much more to /. persica var. purpurea 

 than to the other parent; moreover, a feature that is 

 characteristic of one parent may be accentuated in the 

 hybrid, this being noted especially in the reactions with 

 sodium hydroxide and sodium salicylate. 



Reaction-intensities Expressed by Light, Color, and Tempera- 

 ture Reactions. 

 Polarization: 



I. per. V. pur., moderately high to very high, value 70. 



I. sindjarensis, moderately high to very high, higher than in I. 



persica var. purpurea, value 75. 

 I. pursind, moderately high to high, lower than in either parent, 

 value 65. 

 Iodine: 



I. per. v. pur., moderate, value 55. 



I. sindjarensis, moderate, less than in I. persica var. piu^purea, 



value 50. 

 I. pursind, moderate, the same as in I. sindjarensis, value 50. 

 Gentian violet: 



I. per. V. pur., moderate, value 45. 



I. sindjarensis, moderate, less than in I. persica var. purpurea, 



value 43. 

 I. pursind, light to moderate, less than in either parent, value 40. 

 Safranin: 



I. per. V. pur., moderate, value 50. 



I. sindjarensis, moderate, less than in I. persica var. purpurea, 



value 47. 

 I. pursind, moderate, less than in either parent, value 45. 

 Temperature: ' 



I. per. V. pur., in the majority at 64 to 66°, in all at 68 to 70°, 



mean 69°. 

 I. sindjarensis, in the majority at 63.5 to 65°, in all at 66 to 67°, 



mean 66.5°. 

 I. pursind, in the majority at 64.5 to 66°, in all at 68 to 70°, mean 

 69°. 



The reactivity of I. persica var. purpurea is higher 

 than that of the other parent in the iodine, gentian violet, 

 and safranin reactions, and lower in the polarization and 

 temperature reactions. The reactivity of the hybrid 

 is the same or practically the same as that of I. persica 

 var. purpurea in the temperature reaction; the same 

 or practically the same as that of I. sindjarensis in the 

 iodine reaction ; and the lowest of the -three in the polar- 

 ization, gentian violet, and safranin reactions. The hy- 

 brid is closer to I. persica var. purpurea than to the 

 other parent in the polarization and temperature reac- 

 tions ; and the reverse in the iodine, gentian violet, and 

 safranin reactions. 



Table A 33 shows the reaction-intensities in percent- 

 ages of total starch gelatinized at definite intervals 

 (minutes). 



Velocity-reaction Curves. 



This section treats of the velocity-reaction curves of 

 the starches of 7m persica var. purpurea, I. sindjarensis, 

 and 7. pursind, showing the quantitative difEerences in 

 the behavior toward different reagents at different time- 

 intervals. ( Charts D 442 to D 462. ) 



The most conspicuous features of this group of curves 

 are: 



(1) The marked closeness of all three curves 

 throughout the various reactions, the only reaction in 

 which there is a marked tendency to continually in- 

 creasing differentiation during the 60 minutes being 



