78 



HISTOLOGIC PROPERTIES AND REACTIONS. 



logic properties the starches of the parents differ in cer- 

 tain well-defined respects. The starch of Narcissus poeti- 

 cus poetarum in comparison with that of the other parent 

 shows in the polarization figure less definition and some 

 differences in the characters of the lines; and in the 

 selenite reaction less clean-cut quadrants, more irregu- 

 larity of shape, more often purity of colors, and more 

 grains with a greenish tinge. With iodine no qualita- 

 tive differences were recorded. In the qualitative reac- 

 tions with the chemical reagents there are well-defined 

 differences which for the most part are related to varia- 

 tions in the histologic peculiarities of the grains of the 

 two plants. The starch of the hybrid in comparison with 

 the starches of the parents contains a larger percentage 

 of aggregates and compound grains than in either parent ; 

 it is more like the starch of N. princess mary as regards 

 the absence of clearness of distinction between the pri- 

 mary and secondary starch deposits; but it is, on the 

 whole, in closer relationship to the starch of N. poeticus 

 poetarum. In the character and eccentricity of the 

 hilurn and size of the grains the relationship is closer 

 to N. princess mary, but in the character of the lamellae 

 it is nearer the other parent. In character of the 

 polariscopic figure, and in the reactions with selenite, 

 the relationship is closer to N. princess mary. In the 

 qualitative iodine reaction it is closer to N. poeticus 

 poetarum. In all of the qualitative reactions with the 

 chemical reagents (including chloral hydrate, chromic 

 acid, pyrogallic acid, nitric acid, and sulphuric acid) 

 characteristics of each of the parents are evident and also 

 certain individualities not observed in the parents, but 

 the resemblances of the hybrid, as a whole, are closer to 

 N. princess mary than to N. poeticus poetarum. 



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

 ture Reactions. 

 Polarization: 



N. princess mary, low to high, value 35. 



N. poeticus poetar., low to high, higher than in N. princess mary, 



value 40. 



N. cresset, low to high, same as in N. poeticus poetarum, value 40 

 Iodine: 



N. princess mary, light to moderate, value 42. 



N. poeticus poetar., light to moderate, slightly higher than in 



N. princess mary. value 45. 

 N. cresset, light to moderate, the same as in N. poeticus poetarum, 



value 45. 

 Gentian violet: 



N. princess mary, light to moderate, value 37. 



N. poeticus poetar., light to moderate, slightly lighter than in 



N. princess mary, value 35. 

 N. cresset, light to moderate, the same as in N. princess mary, 



value 37. 

 Safranin: 



N. princess mary, moderate, value 50. 



N. poeticus poetar, moderate, the same as in N. princess mary. 



value 50. 



N. cresset, moderate, the same as in both parents, value 50. 

 Temperature: 



N. princess mary, in majority at 70 to 72, in all at 74 to 76, 



mean 75. 

 N. poeticus poetar., in majority at 67 to 69, in all at 71 to 73, 



mean 72. 

 N. cresset, in majority at 71 to 73, in all at 74.5 to 76, mean 75.7. 



The reactivity of N. princess mary is the same or 

 practically the same as that of the other parent in the 

 safranin reaction ; higher in the gentian-violet reaction : 

 and lower in the polarization, iodine, and temperature 

 reactions. The reactivity of the hybrid is the same or 

 practically the same as that of N. princess mary with 



gentian violet; the same or practically the same as that 

 of the other parent in the polarization and iodine reac- 

 tions; the same as that of both parents with safranin; 

 and the lowest of the three with temperature, but nearer 

 N. princess mary. 



Table A 17 shows the reaction-intensities in percent- 

 ages of total starch gelatinized at definite intervals 

 (minutes) : 



TABLE A 17. 



VELOCITY-REACTION CURVES. 



This section deals with the velocity-reaction curves 

 of the starches of Narcissus princess mary, N. poeticus 

 poetarum, and N. cresset, showing quantitative differ- 

 ences in the behavior toward different reagents at definite 

 time-intervals. (Charts D 299 to D 304.) 



The most conspicuous features of these charts are: 



(1) The closeness of all three curves in all of the 

 charts (with the exception of the very quick sulphuric- 

 acid reaction in which there is no differentiation) and the 

 moderate to low or very low reactivities. In the sul- 

 phuric-acid reaction gelatinization proceeds so rapidly 

 that there is differentiation only before the end of about 

 3 minutes, at the end of 2 minutes the reactions of N. 

 princess mary and the hybrid are practically absolutely 

 the same, but the reaction of the other parent is distinctly 

 less. In the reaction with chloral hydrate there is unim- 

 portant separation of the curves, but in the other three 

 reactions there are varying degrees of separation. 



(2) The relationships of the parental curves to each 

 other and to the curve of the hybrid vary in the different 

 reactions and during the progress of the reactions. 



(3) The curve of 2V. princess mary is the highest in 

 the reaction with pyrogallic acid ; lowest with chloral 

 hydrate; intermediate with nitric acid; and practically 

 the same as that of the hybrid and higher than the curve 

 of the other parent with chromic acid. 



(4) The hybrid curve is the highest of the three in 

 the reactions with chloral hydrate and nitric acid; it 

 tends to be the lowest with pyrogallic acid; and it in- 

 clines to be the lowest at first and the highest later with 

 chromic acid. It is more closely related to the curve of 

 2V. princess mary in the reaction with chloral hydrate ; 

 to the curve of the other parent with nitric acid ; and first 



