66 



HISTOLOGIC PROPERTIES AND REACTIONS. 



The two hybrids show in general a closer relation- 

 ship in their reactivities to each other than does either 

 to either parent. In some reactions the reactivities are 

 the same, and in others one hybrid has a higher reactivity 

 than the other, but in other reactions the reverse. Then 

 again their reactivities in their parental relationships are 

 of a most variable character in that in a given reaction 

 both may be lower or higher than the reactions of the 

 parents, in another reaction that of one may be higher 

 and that of the other lower, or intermediate, or the same, 

 etc. Thus, eliminating the seven reactions in which, 

 owing to a too rapid or too slow reaction, the results were 

 the same in case of all four starches, it will be noted 

 that out of the remaining 19 reactions in only 6 were 

 the reactions of the same relationship to the parents — 

 in the polarization reactions the reactivities of both hy- 

 brids are the lowest and both nearer the seed parent; in 

 the temperature reactions one is higher than either 

 parent, but closer to the seed parent, and the other is 

 practically the same as the seed parent ; in the nitric acid 

 reactions both are the highest, in the former nearer the 

 seed parent and in the latter nearer the pollen parent; 

 in the hydrochloric acid reactions the reactivities are 

 lowest, and both as close to one as to the other parent; 

 in the sodium-hydroxide reactions both are highest and 

 nearer the seed parent ; and in the sodium-salicylate reac- 

 tions both are the same as the pollen parent. In each 

 of the other reactions one hybrid shows a parental rela- 

 tionship that is different from that of the other. Thus, 

 in the iodine reactions N. giantess is closer to the seed 

 parent, while N. abundance is closer to the pollen parent; 

 in the sulphuric-acid reactions N. giantess is closer to 

 the pollen parent, while N. abundance is closer to the 

 seed parent; in the potassium-sulphide reactions both 

 hybrids are intermediate, but one is closer to the pollen 

 parent and the other to the seed parent, etc. The reac- 

 tivities of N. giantess are, on the whole, slightly higher 

 than those of the other hybrid, and both are in this 

 respect nearer the pollen than the seed parent, N. giantess 

 being the closer. 



The following is a summary of the reaction-intensi- 

 ties of the hybrids as regards sameness, intermediateness, 

 excess, and deficit in relation to the parents : 



Same or practically same as- 



Seed parent 



Pollen parent 



Both parents 



Intermediate 



Highest 



Lowest 



N. giantess. 



N. abundance. 



In both hybrids the properties seem to be influenced 

 much more by the pollen parent. In the first hybrid 

 there is greater tendency to intermediateness and less 

 tendency to lowness of reactivity than in the other hy- 

 brid. The hybrids differ sufficiently in their parental 

 relationships to be readily distinguished notwithstanding 

 their close similarities. (See Chapter V.) 



12. OoMPAEiso]srs OF THE Staeches oe Neeine 



SAENIEWSIS VAB. COEUSCA MAJOE, IST. CUEVIFOLIA 

 VAE. EOTHEEGILLI MAJOE, AND N". GLOEY OF 



SABNIA. 



In histologic characteristics, polariscopic figures, 

 reactions with selenite, qualitative reactions with iodine, 

 and qualitative reactions with the various chemical reag- 

 ents all three starches exhibit properties in common, and 

 each has certain individualities, but all are closely 



related. The starch of N. curvifolia var. fothergiUi 

 major contains in comparison with the starch of the 

 other parent a larger number of compound grains and 

 aggregates, and the former are of more varied types. 

 The grains are less regular and somewhat more slender 

 and pointed. The hilum is more distinct and eccentric. 

 The lamellse are more distinct and less numerous, and 

 there is difference in the grouping of the coarse lamellse. 

 The size is less and the grains tend to be less broad 

 in proportion to length. In the polariscopic, selenite, 

 and iodine reactions differences are noted. In the quali- 

 tative reactions with the chemical reagents many simi- 

 larities and differences are recorded, some of the latter 

 being quite striking, and taken collectively readily dif- 

 ferentiate the starches. The starch of the hybrid con- 

 tains fewer compound grains and aggregates than are 

 found in the parents, and the types of compound grains 

 are for the most part those observed in the starch of 

 N. sarniensis var. corusca major. The grains are more 

 regular in form than in either parent, and on the whole 

 nearer those of N. sarniensis var. corusca major. The 

 characters of the hilum are closer to those of the same 

 parent, and the eccentricity is less than in either parent. 

 The lamellse are less distinct but more numerous than 

 in either parent, and they are more closely related to those 

 of N. sarniensis var. corusca major. In sizes the grains 

 are also more closely related to the same parent. In the 

 qualitative polarization, selenite, and iodine reactions the 

 hybrid shows a more marked closeness to N. sarniensis 

 var. corusca major. In the qualitative reactions with the 

 chemical reagents, including ichoral hydrate, nitric acid, 

 potassium iodide, potassium sulphocyanate, potassium 

 sulphide, and sodium salicylate, reactions in each re- 

 sembling more closely those of one or the other parent are 

 noted, but in case of each reagent the phenomena are 

 collectively closer to those of N. sarniensis var. corusca 

 major than to those of the other parent. 



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

 ture Reactions. 

 Polarization: 



N. sarn. var. cor. maj., moderate to very high, value 90. 



N. curvi. var. foth. maj., moderate to very high, lower than N. 



sarn. var. cor. maj., value 87. 

 N. glory of sarnia, moderate to very high, the same as N. sarn. 

 var. cor. maj., value 90. 

 Iodine: 



N. sarn. var. cor. maj., moderately deep, value 60. 



N. curvi. var. foth. maj., moderately deep, deeper than N. sarn. 



var. cor. maj., value 65. 

 N. glory of sarnia, moderate, less than either parent, value 65. 

 Gentian violet : 

 N. sarn. var. cor. maj., light to moderate, value 40. 

 N. curvi. var. foth. maj., moderate, deeper than N. sarn. v. cor. 



maj., value 45. 

 N. glory of sarnia, light to moderate, lighter than in either parent, 

 value 35. 

 Safranin: 



N. sarn. var. cor. maj., moderate, value 40. 



N. curvi. var. foth. maj., moderate, deeper than N. sarn var. cor. 



maj., value 35. 

 N. glory of sarnia, light to moderate, less than either parent, 

 ■ value 35. 

 Temperature : 



N. sarn. var. cor. maj., in the majority at 70 to 71°, in all but rare 



grains 76 to 78.8°, mean 78.4°. 

 N. curvi. var. foth maj., in the majority at 68.1 to 69°, in all at 



73.2 to 74.3°, mean 73.8°. 

 N. glory of sarnia, in the majority at 70 to 72° in all at 75.8 to 77°, 

 mean 76.4°. 



N. sarniensis var. corusca major shows in the polariza- 

 tion and temperature reactions higher reactivities than 

 the other parent, but lower reactivities in those with 

 iodine, gentian violet, and safranin. The hybrid shows 

 the same reactivity as N. sarniensis var. corusca major in 

 the polarization reaction, but less than that of the other 

 parent; lower reactivities than the parents with iodine. 



