106 



HISTOLOGIC PROPERTIES AND REACTIONS. 



31. COMPARISONS OF THE STARCHES OF IRIS IBERICA, 

 I. CENGIALTI, AND I. DORAK. 



In histologic characteristics, polariscopic figures, reac- 

 tions with selenite, reactions with iodine, and qualitative 

 reactions with various chemical reagents, the starches 

 of the parents and hybrid exhibit properties in common 

 in varying degrees of development, the sum of which 

 in each case is characteristic of the starch. The three 

 starches are very much alike, and notwithstanding the 

 very close resemblances of the parental starches the 

 hybrid starch shows clearly evidence of biparental in- 

 heritance. The starch of Iris iberica in comparison with 

 that of /. cengialti contains more compound grains and 

 aggregates, and there are two types of compound grains 

 in the former that are not present in the latter; the 

 grains are not quite so regular in form; and elongated 

 elliptical grains are more common, but ovoid forms less 

 common. The hilum is more distinct, less often fis- 

 sured, and more eccentric. The lamellae are less dis- 

 tinct, not quite so coarse, and more numerous. The size 

 is somewhat less, with variations in ratio of length to 

 width that are interesting. In -the polariscopic, seleuite, 

 and qualitative reactions there are various differences. 

 In the qualitative reactions with chloral hydrate, hydro- 

 chloric acid, potassium iodide, sodium hydroxide, and 

 sodium salicylate, there are many differences and indi- 

 vidualities, several of the latter being quite striking. 

 The starch -of the hybrid in comparison with the parental 

 starches contains more compound grains and aggregates 

 than in either parent, and the compounds are of the two 

 types found in /. iberica, but not in the other parent; 

 the grains are less regular than in either parent. The 

 relationship is on the whole distinctly closer to 7. iberica. 

 The hilum in character is closer to 7. iberica, but in 

 eccentricity to the other parent. The lamellae in charac- 

 ter are closer to I. cengialti, but in number to 7. iberica. 

 The size is somewhat less than in either parent, and, on 

 the whole, closer to 7. cengialti. In the polariscopic, 

 selenite, and qualitative iodine reactions there are lean- 

 ings here and there toward one or the other parent, but, 

 on the whole, the relationship is much closer to 7. iberica. 

 In the qualitative chemical reactions the latter statement 

 holds with equal force. 



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

 ture Reactions. 

 Polarization: 



I. iberica, low to high, value 50. 



I. cengialti, moderately high to high, higher than in I. iberica, 

 value 60. 



I. dorak, low to high, the same a3 in I. iberica, value 50. 

 Iodine: 



I. iberioa, light to moderate, value 40. 



I. cengialti, moderate, deeper than in I. iberica, value 45. 



I. dorak, light to moderate, the same as in I. iberica, value 40. 

 Gentian violet: 



I. iberica, light to moderate, value 40. 



I. cengialti, moderate, deeper than in I. iberica, value 45. 



I. dorak, moderate, deeper than in either parent, value 50. 

 Safranin: 



I. iberica, moderate, value 45. 



I. cengialti, moderate, deeper than in I. iberica, value 50. 



I. dorak, moderate, the same as in I. cengialti, value 50. 

 Temperature: 



I. iberica, in the majority at 09 to 70, in all at 71 to 72.5, mean 

 71.5. 



I. cengialti, in the majority at 70 to 72 mean, in all at 74 to 76, 

 mean 75. 



I. dorak, in the majority at 68 to 70, in all at 70 to 72, mean 71.5. 



The reactivity of 7. iberica is lower than that of the 

 other parent in the polarization, iodine, gentian violet, 

 and safranin reactions, and higher in the temperature 

 reaction. The reactivity of the hybrid is the same or 

 practically the same as that of 7. iberica in the reactions 

 with polarization and iodine; the same or practically the 



