44 



HISTOLOGIC PROPERTIES AND REACTIONS. 



acid; the low reactions with nitric acid, potassium hy- 

 droxide, and potassium sulphocyanate ; and the very low 

 reactions with chloral hydrate, potassium iodide, potas- 

 sium sulphide, sodium hydroxide, sodium sulphide, cal- 

 cium nitrate, uranium nitrate, strontium nitrate, cobalt 

 nitrate, copper nitrate, cupric chloride, barium chloride, 

 and mercuric chloride. 



The following is a summary of the reaction-intensi- 

 ties: 



4. COMPARISONS OF THE STARCHES OF HIPPEASTRUM 

 D.5X)NES, H. ZEPHYR, AND H. DRONES-ZEPHYR. 

 In histologic characteristics, polariscopic figures, 

 reactions with selenite, qualitative reactions with iodine, 

 and qualitative reactions with the various chemical reag- 

 ents the starches of the parents exhibit properties in 

 common and certain individualities, but generally a very 

 close correspondence throughout. The grains of H. 

 zephyr in comparison with those of the seed parent are 

 found to include less numbers of aggregates and com- 

 pounds; they are free from the long, narrow finger-like 

 grains found in the latter; they are more regular, the 

 protuberances being less numerous and not so large. 

 The hilum is less distinct and less frequently fissured. 

 The lamellae are less distinct, less fine, and less in num- 

 ber. The common size is about the same, but the large 

 grains show some differences in ratio of length to breadth. 

 The polariscopic, selenite, and qualitative iodine reac- 

 tions exhibit some minor differences. The starch of the 

 hybrid in comparison with the starches of the parents 

 contains a relatively larger number of aggregates and 

 compounds but none of the long, narrow finger-like grains 

 found in 77. dceones but not in H. zephyr. The hilum is 

 more frequently fissured than in either parent, and in 

 character and eccentricity it is closer to H. dceones. The 

 lamellae in character and number are nearer to H. dceones. 

 The common size of the grains is somewhat less than in 

 either parent, and the size of the larger grains approaches 

 nearer that of H. zephyr. In the qualitative polariscopic 

 properties the leaning is in certain respects toward one 

 parent and in other respects toward the other, and in 

 the selenite reactions there is development of properties 

 in excess of the development in the parents, with a lean- 

 ing closer to the pollen parent. The qualitative iodine 

 reactions are closer to 11. zephyr. In the qualitative 

 chemical reactions with chloral hydrate, nitric acid, po- 

 tassium iodide, and potassium sulphocyanate the hybrid 

 is closer to 77. dceones, while in the sodium-salicylate 

 reactions the relationship to the two parents is of equal 

 degree. 



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

 ture Reactions. 

 Polarization: 



H. dfflones, high to very high, value 80. 



H. zephyr, high to very high, little higher than in H. dceones, 



value 83. 

 H. dteon. zeph., high to very high, higher than in the parents, 



value 85. 

 Iodine: 



H. djeones, moderate to moderately deep, value 55. 

 H. zephyr, moderate, less than in II. daxmes, value 50. 

 H. deon.-zi'i>h., moderate, same as in H. zephyr, value 50. 

 Gentian violet: 



H. dseones, moderate to moderately deep, value 58. 



H. zephyr, moderate to moderately deep, lighter than in H. deeones, 



value 55. 

 H. dffion.-zeph., moderate, lighter than in either parent, value 50. 



Safranin: 



H. dseones, moderate to moderately deep, value 55. 



H. zephyr, moderate to moderately deep, the same as in H. deeones, 



value 55. 

 H. dseon.-zeph., moderate to moderately deep, the same as in both 



parents, value 55. 

 Temperature : 



H. daxmes, in majority at 72.5 to 74", in all but rare grains at 74 to 



75, mean 74.5. 

 H. zephyr, in the majority at 72 to 73, in all but rare grains at 



73 to 75, mean 74. 

 H. dseon.-zeph., in the majority at 72 to 73, in all but rare grains 



at 72 to 73, mean 72.5. 



The reactivities of 77. dceones are lower than those 

 of the other parent in the polarization and temperature 

 reactions, higher in the iodine and gentian-violet reac- 

 tions, and the same in the safranin reaction. The reac- 

 tivities of the hybrid are higher than those of either 

 parent in the polarization and temperature reactions, 

 lower than that of either parent in the gentian-violet 

 reaction, the same as that of the pollen parent in the 

 iodine reaction, and the same as those of both parents 

 in the safranin reactions. On the whole the inclination 

 is toward the pollen parent. 



Table A 4 shows the reaction-intensities in percent- 

 ages of total starch gelatinized at definite intervals 

 (minutes) : 



VELOCITY-REACTION CURVES. 



The following section treats of the velocity-reaction 

 curves of the starches of Hippeastrum dceones, 77. zephyr, 

 and 77. dceones-zephyr, showing the quantitative differ- 

 ences in the behavior toward different reagents at defi- 

 nite time-intervals. (Charts D 64 to D 84.) 



As noted in the preceding sections the three starches 

 are very closely alike, exhibiting only minor differences, 

 but not infrequently character developments of the hy- 

 brid that exceed the parental extremes. The most con- 

 spicuous features of these charts are : 



(1) The nearness of the three curves throughout. 



(2) The curve of 77. dceones is higher than the curve 

 of 77. zephyr in the reactions with chloral hydrate, chro- 

 mic acid, pyrogallic acid, nitric acid, sulphuric acid, 

 hydrochloric acid, potassium iodide, potassium sulpho- 

 cyanate, sodium hydroxide, and sodium sulphide through 

 the 60 minutes. It also tends to be above in the reac- 

 tion with strontium nitrate. In the sodium-salicylate 

 reaction, in which gelatinization goes on with moderate 

 rapidity, the curves are about the same; and in the reac- 

 tions with potassium sulphide, calcium nitrate, uranium 

 nitrate, cobalt nitrate, copper nitrate, cupric chloride, 

 barium chloride, and mercuric chloride gelatinization 

 proceeds so slowly that there is little or no differentiation. 

 From these data 77. dceones has, on the whole, the higher 

 reactivity. 



(3) The curves of the hybrid show varying relation- 

 ships to the parental curves, in some instances being the 

 same as that of one or the other parent or both parents, 

 in others intermediate, and in others higher or lower than 

 both parental curves. (See following section.) 



(4) Evidence of a preliminary period of comparative 

 resistance is apparent in several of the charts. 



(5) The earliest period at which the three curves 

 are best separated for differential purposes is variable. 

 In the very slow reactions no differentiation seems pos- 

 sible even at the end of 60 minutes, the differences noted 

 being wholly within the limits of error of observation and 

 of no significance whatsoever. The best period for sul- 

 phuric acid is at 5 minutes; for chromic acid, pyro- 

 gallic acid, hydrochloric acid, potassium sulphocyanate, 

 sodium hydroxide and sodium salicylate at 15 minutes; 

 for sodium sulphide at 30 minutes ; for strontium nitrate 

 at 45 minutes ; and for chloral hydrate, nitric acid, and 

 potassium iodide at 60 minutes. 



