40 



HISTOLOGIC PROPERTIES AND REACTIONS. 



derce alba and 7?. sanderce than to B. tubergeni; in the 

 temperature reactions it differs little from those of B. 

 sanderce alba and B. sanderce, but much from those of 

 B. tubergeni; while in the potassium-iodide and sodium- 

 hydroxide read er to B. tubergeni than to the 

 other hybrids. From the foregoing it seems obvious that 

 this plant is not to be identified with either B. tuber- 

 geni or the sanderce hybrids, although closely related. It 

 seems probable, as suggested by Tubergen, that the 

 parentage of A. parkeri on the Amaryllis side was A. 

 belladonna var. blanda (A. blanda Gawi) — the histo- 

 logic and polariscopic properties and the iodine, aniline, 

 and temperature reactions pointing to the same direction 

 of the cross as of B. sanderw alba and B. sandene, while 

 the potassium iodide and sodium hydroxide reactions 

 indicate a cross in the opposite direction ; but the tem- 

 perature reaction alone is almost if not conclusive. Addi- 

 tional studies of the reactions would undoubtedly make 

 absolutely positive the direction of the cross if A. parkeri 

 is a hybrid. 



2. Comparisons of the Starches of Hippeastrum 

 titan, h. cleonia, and h. titan-cleonia. 

 In histologic characteristics, polariscopic figures, 

 reactions with selenite, qualitative reactions with iodine, 

 and qualitative reactions with the various chemical reag- 

 ents these three starches are very much alike. The 

 starch of Hippeastrum cleonia is distinguished from that 

 of the other parent chiefly in the larger number of com- 

 pound grains and aggregates; the presence of isolated 

 grains each having a large pressure facet; more round- 

 ness but greater irregularity of the grains; somewhat less 

 fissuration and less eccentricity of the hilum; more dis- 

 tinct and more regular lamella?; somewhat larger average 

 size of the grains; larger number of double and multiple 

 polariscopic figures; greater frequency of equality of 

 size, less frequency of irregularity of shape, and less often 

 purity of color of the quadrants in the selenite reaction ; 

 and sonic slight differences in qualitative reactions with 

 iodine. The starch of the hybrid is in form, hilum, and 

 polariscopic figure more closely related to the seed 

 parent; and in distinctness and regularity of the lamella?, 

 size, and iodine reactions more closely related to the 

 other parent. In the selenite reactions certain properties 

 lean to one or the other parent. A given character may 

 appear more conspicuously in the hybrid than in either 

 parent. The qualitative reactions with chloral hydrate, 

 nitric acid, potassium iodide, potassium sulphocyanate, 

 and sodium salicylate are closer to those of seed parent. 



Reaction intensities Expressed by Light, Color, and Tempera- 

 ture Reactions. 

 Polarization: 



II. titan. high to very high, value S3. 



II. cleonia, high to very high, lower than in II. titan, value 80. 



II. titan-cleonia, high to very high, higher tlinn in either parent, 



value 85. 

 Iodine: 



H. titan, moderate, valuo 62. 



H. cleonia, moderately deep, deeper than in H. titan, value 55. 



H. titan-oleonia, moderate to deep, deeper than in the parents, 



value 58. 

 Gentian violet: 



II. titan, moderately light to light, value 45. 

 11. cleonia, moderate, deeper than in H. titan, value 50. 

 H. titan-cleonia, moderate, the name as in //. cleonia, value 50. 

 Safranin: 



II. titan, moderate, value 50. 



H. cleonia, moderate, a little deeper than in H. titan , value 55. 

 H. titan-cleonia, moderate, the Rame as in II. cleonia, value 55. 

 Temperature of gelatinization: 



II. titan, in majority at 71 to 75°, in all hut rare grains at 77 to 77.5°, 



mean 77.25°. 

 H. cleonia, in majority at 71 to 73°, in all but rare grains at 73 to 



74°, mean 73.5°. 

 H. titan-cleonia, in majority at 72 to 74°, in all but rare grains at 



73 to 74°, mean 73.6°. 



The reactivity of Hippeastrum titan is higher than 

 that of Hippeastrum cleonia in the polarization reaction, 

 and lower in the reactions with iodine, gentian violet, 

 safranin, and temperature. The hybrid shows in the 

 polarization and iodine reactions the highest reactivi- 

 ties of all three starches; in the reactions with gentian 

 violet, safranin, and temperature the same reactivities 

 as those of Hippeastrum cleonia, all three reactions being 

 higher than the corresponding reactions of the other 

 parent. 



Table A 2 shows the reaction intensities in per- 

 centages of total starch gelatinized at definite intervals 

 (minutes). 



Velocity-reaction Curves. 



This section treats of the velocity-reaction curves of 

 the starches of Hippeastrum titan, II. cleonia. and //. 

 titan-cleonia, showing the quantitative differences in the 

 behavior Inward different reagents at definite time-inter- 

 vals. (Charts D 22 to D 42.) 



Among the conspicuous features of these charts are : 



(1) The closeness of the curves of the three starches 

 in all of the reactions. The reactions are so slow with 

 potassium iodide, potassium sulphide, sodium sulphide, 

 calcium nitrate, uranium nitrate, strontium nitrate, co- 

 balt nitrate, copper nitrate, cupric chloride, barium chlo- 

 ride, and mercuric chloride that there is almost if not 

 absolutely no differentiation. Omitting the foregoing 

 reactions, the curve of Hippeastrum titan is higher than 

 that of the other parent in the reactions with chromic 

 acid and sulphuric acid, and lower in those with chloral 

 hydrate, pyrogallic acid, nitric acid, potassium hydrox- 

 ide, potassium sulphocyanate, sodium hydroxide, and so- 

 dium salicylate, indicating, on the whole, a lower reac- 

 tivity of this starch. 



(2) The curves of the hybrid show marked variations 

 in their parental relationships, with as much of a ten- 

 dency to be higher or lower than the parental curves as 

 to intermediateness. In a few reactions the curves aTe 

 the same as those of the seed parent or of the pollen 

 parent, and in about one-third they are the same as the 

 parental curves. (See following section.) 



(3) In most of the charts in which there was a mod- 

 erate to rapid reactivity there are indications of an early 

 period of comparatively marked resistance. 



(4) The best period during the 60 minutes for the 

 differentiation of the three starches is variable, and in 

 case of all the very slow reactions and including those 

 with chloral hydrate, nitric acid, potassium sulphocya- 

 nate, and sodium hydroxide, the curves are best separated, 

 if at all, at the end of 60 minutes. This period is noted 

 at the end of 15 minutes in the reactions with chromic 

 acid, pyrogallic acid, sulphuric acid, potassium hydrox- 

 ide, and sodium salicylate; at the end of 3(1 minutes with 

 hydrochloric acid; and at the end of 60 minutes wiih 

 the other reagents. 



Eeaction-intensities of the IIybrid. 



This section treats of the reaction-intensities of the 

 hybrid as regards sameness, intermediateness, excess, and 

 deficit in relation to the parents. (Table A 2 and Charts 

 D22 to 1)42.) 



The reactivities of the hybrid are the same as those 

 of the seed parent in the reactions with sodium sulphide 

 and strontium nitrate; the same as those of the pollen 

 parent with gentian violet, safranin, and temperature; 

 the same as those of both parents with potassium sul- 

 phide, calcium nitrate, uranium nitrate, cobalt nitrate, 

 copper nitrate, cupric chloride, barium chloride, and 

 mercuric chloride, in all of which the reactions are ex- 

 ceedingly slow; intermediate with nitric acid, hydro- 

 chloric acid, potassium iodide and potassium sulpho- 



