120 



HISTOLOGIC PROPERTIES AND REACTIONS. 



are chromic acid, barium chloride, and mercuric chloride 

 in 15 minutes, pyrogallic acid in 30 minutes, and cobalt 

 nitrate in 45 minutes. 



EEACTION-INTENSITIES OF THE HYBRID. 



This section treats of the reaction-intensities of the 

 hybrid as regards sameness, intennediateness, excess, 

 and deficit in relation to the parents. (Table A 36 and 

 Charts D 515 to D 526.) 



The reactivities of the hybrid are the same as those 

 of the seed parent in the reactions with iodine, gentian 

 violet, safrauin, temperature, nitric acid, hydrochloric 

 acid, potassium iodide, potassium sulphocyauate, and 

 potassium sulphide; the same as those of the pollen 

 parent in none; the same as those of both parents in 

 the reactions with sulphuric acid and potassium hydrox- 

 ide; intermediate with chloral hydrate, chromic acid, 

 pyrogallic acid, sodium hydroxide, sodium sulphide, so- 

 dium salicylate, calcium nitrate, uranium nitrate, stron- 

 tium nitrate, cobalt nitrate, copper nitrate, cupric 

 chloride, barium chloride, and mercuric chloride (in all 

 14 being nearer the seed parent) ; highest in none ; and 

 lowest in the polarization reaction, in which it is as close 

 to one as to the other parent. 



The following is a summary of the reaction-intensi- 

 ties : Same as seed parent, 9 ; same as pollen parent, ; 

 same as both parents, 2; intermediate, 14; highest, 0; 

 lowest, 1. 



Sameness as the seed parent and intennediateness 

 with a universal inclination to the seed parent are very 

 conspicuous features of these data. In the two reactions 

 wherein all three starches are the same the reactions 

 occurred with such rapidity as not to permit of differen- 

 tiation, and in the polarization reaction in which the 

 hybrid shows the lowest reactivity of the three and is as 

 closely related to one as to the cither parent the crudity 

 of the method of valuation of the reaction has not brought 

 out differences that probably exist. The properties of 

 the starch seem to have been determined primarily by 

 the seed parent, the effect of the other parent being 

 expressed in the lowering of reactive-intensities, varying 

 in degree in the different reactions, but never so far as to 

 the point of mid-intermediateness. 



COMPOSITE CURVES OF THE EEACTION-INTENSITIES. 



This section treats of the composite curves of the 

 reaction-intensities, showing the differentiation of the 

 starches of Begonia single crimson scarlet, B. socotrana, 

 and B. mrs. heal. (Chart B 36.) 



The most conspicuous features of this chart are: 



(1) The generally close accord of the curves of B. 

 single crimson scarlet and the hybrid and the extraordi- 

 narily erratic course of the curve of B. socotrana through- 

 out most of the chart. The hybrid, which is a tub'erous 

 form, follows very closely, as a rule, the reactivities of the 

 first parent, which is also tuberous, while the other 

 parent, which is semituberous (bulbils), has a very differ- 

 ent type of curve far more different from that of the 

 other parent than was recorded in the curves of the 

 tender and hardy crinums and the rhizomatous anc 

 tuberous irises. 



(2) The curve of B. single crimson scarlet is higher 

 than the curve of B. socotrana throughout the chart (ex- 

 cepting in the reactions with polarization, sulphuric acid 



and potassium hydroxide, in which they are alike), and 

 m most instances it tends to be very much higher, the 

 only reactions in which there is marked approximation 

 being those with chloral hydrate, potassium sulphide, and 

 sodium salicylate. 



(3) In B. single crimson scarlet the very high reac- 

 tions with chloral hydrate, chromic acid, nitric acid, 

 sulphuric acid y hydrochloric acid, potassium hydrox- 

 ide, potassium iodide, potassium sulphocyanate, potas- 

 sium sulphide, sodium hydroxide, sodium sulphide, 

 sodium salicylate, calcium nitrate, uranium nitrate, 

 strontium nitrate, cobalt nitrate, copper nitrate, cupric 

 chloride, and mercuric chloride; the high reactions with 

 polarization, saf ranin, pyrogallic acid, and cobalt nitrate ; 

 the moderate reactions with iodine, gentian violet, and 

 temperature ; and the low reaction with barium chloride. 



(4) In B. socotrana the very high reactions with 

 chloral hydrate, sulphuric acid, potassium hydroxide, 

 potassium sulphide, and sodium salicylate ; the high reac- 

 tions with polarization and nitric acid; the moderate 

 reactions with saf ranin and chromic acid ; the low reac- 

 tions with iodine, gentian violet, temperature, sodium 

 hydroxide, and strontium nitrate ; and the very low reac- 

 tions with pyrogallic acid, hydrochloric acid, potassium 

 iodide, potassium sulphocyanate, sodium sulphide, cal- 

 cium nitrate, uranium nitrate, cobalt nitrate, copper ni- 

 trate, cupric chloride, barium chloride, and mercuric 

 chloride. 



(5) In the hybrid the very high reactions with chloral 

 hydrate, nitric acid, sulphuric acid, hydrochloric acid, 

 potassium hydroxide, potassium iodide, potassium sulpho- 

 cyanate, potassium sulphide, sodium hydroxide, sodium 

 sulphide, sodium salicylate, calcium nitrate, uranium ni- 

 trate, strontium nitrate, copper nitrate, and cupric chlo- 

 ride ; the high reactions with saf ranin and chromic acid ; 

 the moderate reactions with polarization, iodine, and 

 gentian violet; the low reactions with temperature, 

 pyrogallic acid, and mercuric chloride ; and the very low 

 reactions with cobalt nitrate and barium chloride. 



Following is a summary of the reaction-intensities: 



37. COMPARISONS OF THE STAECHES OF BEGONIA 

 DOUBLE LIGHT EOSE, B. SOCOTEANA, AND B. 



ENSIGN. 



In histologic characteristics, polariscopic figures, reac- 

 tions with selenite, reactions with iodine, and qualitative 

 reactions with various chemical reagents all three starches 

 have properties in common in varying degrees of de- 

 velopment, the sum of which in each case is distinctive 

 of the starch. The starch of Begonia socotrana, in com- 

 parison with that of B. double light rose shows an ab- 

 sence of aggregates and has more numerous irregularities. 

 The hilum is less distinct, somewhat more often fissured, 

 and more eccentric. The lamellae are not so distinct; 

 more distinct at the distal than at the proximal end, 

 instead of sometimes the reverse as in B. donblr light 



