132 



HISTOLOGIC PBOPEBTIES AND KEACTIONS. 



Gentian violet: 



M. vexillaria, moderate, value 50. 



M. rcezlii, moderate to deep, deeper than in M. vexillaria, value 55. 



M. bleuana, moderate to deep, lighter than in M. vexillaria, 

 value 47. 

 Saf ranin : 



M. vexillaria, moderate to moderately deep, value 55. 



M. roezlii, moderate to deep, considerably deeper than in M. vex- 

 illaria, value 65. 



M. bleuana, moderate to moderately deep, the same as in M. vex- 

 illaria, value 55. 

 Temperature: 



M. vexillaria, in the majority at 70 to 71°, in all but rare grains at 

 73 to 74°, mean 73.5°. 



M. rcezlii, in the majority at 74 to 76°, in all but rare grains at 

 76 to 77°, mean 76.5°. 



M. bleuana, in the majority at 69 to 71°, in all but rare grains at 

 72 to 74°, mean 73°. 



M. vexillaria shows a higher reactivity than the 

 other parent in the polarization, iodine, and temperature 

 reactions, and a lower reactivity in the gentian-violet and 

 safranin reactions. The hybrid has the highest reactivi- 

 ties of the three in the polarization and temperature reac- 

 tions, the lowest reactivity in the gentian-violet reactions, 

 and the same or practically the same reactivities as M. 

 vexillaria in the iodine and safranin reactions. In all 

 five reactions the hybrid is either the same as or closer 

 to M. vexillaria. 



Table A 43 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 Miltonia vexillaria, M. rcezlii, and M. 

 hleuana, showing the quantitative differences in the be- 

 havior toward different reagents at definite time-inter- 

 vals. (Charts D 595 to D 609.) 



Among the conspicuous features of these charts are : 

 The closeness and correspondence of the curves in each 

 of the reactions. The reactions with nitric acid, sul- 

 phuric acid, hydrochloric acid, and potassium hydroxide 

 occur with such rapidity that there is practically no 

 differentiation. The curve of M. vexillaria is higher 

 than the curve of the other parent in the reactions vdth 

 chloral hydrate, chromic acid, pyrogallic acid, potassium 

 iodide, potassium sulphocyanate, potassium sulphide, so- 

 dium hydroxide, sodium sulphide, sodium salicylate, cal- 

 cium nitrate, uranium nitrate, strontium nitrate, copper 

 nitrate, cupric chloride, and mercuric chloride ; and lower 

 with cobalt nitrate and barium chloride. The hybrid, 

 while bearing varying relations to one or the other or both 

 parents as regards sameness, intermediateness, excess, 

 and deficit in reactivities, shows a remarkable inclination 

 to an almost universally higher reactivity than either of 

 the parents, and, moreover, a similar inclination to the 

 seed parent ; in only 2 of the 26 reactions is there a mani- 

 fest leaning toward the pollen parent. An early period of 

 high resistance followed by rapid to moderate gelatiniza- 

 tion is entirely absent from this set of reactions. The 

 earliest period during the 60 minutes that is best for the 

 differentiation of the three starches is for chromic acid, 

 potassium iodide, potassium sulphide, potassium sulpho- 

 cyanate, sodium hydroxide, sodium sulphide, sodium 

 salicylate, uranium nitrate, strontium nitrate, cobalt ni- 

 trate, copper nitrate, and cupric chloride at 5 minutes; 

 calcium nitrate at 15 minutes; chloral hydrate, pyro- 

 gallic acid, barium chloride, and mercuric chloride at 30 

 minutes. The reactions with nitric acid, sulphuric acid, 

 hydrochloric acid, and potassium hydroxide are too fast 

 for differentiation of the starches. 



Keaction-intensities of the Hybrid. 

 This section treats of the reaction-intensities of the 

 hybrid as regards sameness, intermediateness, excess, and 



Table A 43. 



