138 



HISTOLOGIC PROPERTIES AND REACTIONS. 



period of high resistance followed by a rapid to moderate 

 gelatinization is not noticeable excepting the reactions 

 with chromic acid, pyrogallic acid, and sodium salicylate 

 with C. vestita var. rubro-oculata, and in the pyrogallic- 

 acid reaction with the hybrid C. bryan. The earliest 

 period during the CO minutes at which it is best for the 

 differentiation of the three starches seems, for chromic 

 acid, sulphuric acid, hydrochloric acid, potassium hy- 

 droxide, and sodium salicylate, at 5 minutes; for pyro- 

 gallic acid at 10 minutes; and for chloral hydrate and 

 nitric acid at 15 minutes. 



EEACTION-INTENSITIES OF THE HYBRID. 



This section treats of the reaction-intensities of the 

 hybrid as regards sameness, intermediateness, excess, and 

 deficit in relation to the parents. (Table A 46 and 

 Charts D 627 to D 634.) 



The reactivities of the hybrid are the same as those 

 of the seed parent in the potassium-hydroxide reaction; 

 the same as those of the pollen parent or both parents in 

 none; intermediate in the polarization, iodine, gentian 

 violet, safranin, temperature, chloral hydrate, chromic 

 acid, pyrogallic acid, nitric acid, sulpuuric acid, and 

 sodium salicylate reactions (in 1 being closer to the 

 seed parent, in 4 closer to the pollen parent, and in 5 

 being mid-intermediate) ; highest in the hydrochloric- 

 acid reaction, and closer to the pollen parent; and the 

 lowest in none. 



The following is a summary of the reaction-intensi- 

 ties : Same as seed parent, 1 ; same as pollen parent, ; 

 same as both parents, 0; intermediate, 11; highest, 1; 

 lowest, 0. 



The pollen parent seems to have been more effective 

 than the seed parent in determining the characters of the 

 starch of the hybrid. Intermediateness is quite marked, 

 and in about one-half of these reactions there is mid- 

 intermediateness. 



COMPOSITE CURVES OF THE REACTION-INTENSITIES. 



This section treats of the composite curves of the 

 reaction-intensities, showing the differentiation of the 

 starches of Calanthe vestita var. rubro-oculata, C. reg- 

 nieri, and C. bryan. (Chart E46.) 



The most conspicuous features of this chart are : The 

 very close correspondence in the rises and falls of all 

 three curves excepting in the chloral-hydrate reactions, 

 in which the curve of C. vestita var. rubro-oculata falls 

 instead of rises in harmony with the curves of the other 

 parent and the hybrid, as in the preceding set of Calan- 

 the. The marked separation of the curves of the two 

 parents in the reactions with polarization, chloral hy- 

 drate, chromic acid, pyrogallic acid, and nitric acid, and 

 their closeness in the others. The tendency in general 

 for the curve of the hybrid to have a position of some 

 degree of intermediateness and with an apparent closer 

 relationship to C. regnieri than to the other parent. The 

 higher position of the curve of C. vestita var. rubro- 

 oculata than that of the other parent in the reactions 

 with polarization, iodine, gentian violet, safranin, and 

 temperature; and the lower positions with chloral hy- 

 drate, chromic acid, pyrogallic acid, nitric acid, sulphuric 

 acid, hydrochloric acid, and potassium hydroxide. In 



C. vestita var. rubro-oculata the very high reaction with 

 sulphuric acid; the high reactions with polarization and 

 safranin; the moderate reactions with iodine, gentian 

 violet, and chromic acid ; and the low reactions with tem- 

 perature, chloral hydrate, pyrogallic acid, nitric acid, 

 hydrochloric acid, and potassium hydroxide. In C. reg- 

 nieri the very high reactions with chloral hydrate and 

 sulphuric acid ; the high reactions with safranin, chromic 

 acid, pyrogallic acid, and nitric acid ; the moderate reac- 

 tions with gentian violet, hydrochloric acid, and potas- 

 sium hydroxide ; and the low reactions with polarization, 

 iodine, and temperature. In the hybrid C. bryan the 

 high reaction with sulphuric acid ; the high reactions with 

 safranin and chromic acid ; the moderate reactions with 

 polarization, gentian violet, chloral hydrate, chromic acid, 

 pyrogallic acid, and hydrochloric acid ; and the low reac- 

 tions with iodine, temperature, nitric acid, and potassium 

 hydroxide. 



Following is a summary of the reaction-intensities 

 (12 reactions) : 



NOTES ON THE CALANTHES. 



In comparing the two composite-curve charts it will 

 be observed that the curves correspond with sufficient 

 closeness to indicate a common generic type. The three 

 parents show marked closeness (or even a practical iden- 

 tity) in the reactions with iodine, gentian violet, safra- 

 nin, temperature, sulphuric acid, and potassium hydrox- 

 ide; but more or less marked differences in those with 

 polarization, chloral hydrate, chromic acid, pyrogallic 

 acid, nitric acid, and hydrochloric acid. The greatest 

 interest in these charts doubtless centers in the differ- 

 ences in the relations of the hybrid curves to the parental 

 curves, in the first set the hybrid curve tending in gen- 

 eral to follow more closely the parent (seed parent) hav- 

 ing the higher mean reactivity, and in the second set 

 to follow more closely the parent (pollen parent) having 

 the lower mean reactivity. In both sets C. vestita var. 

 rubro-oculata is a parent, in one the pollen parent and 

 in the other the seed parent, but in neither does the 

 hybrid show as much closeness to it as to the other parent. 

 The relations of the hybrid curves as regards sameness, 

 intermediateness, and excess are quite different, as indi- 

 cated in the summaries. Owing to peculiarities of the 

 grains of Calanthe referred to in Part II, page 769, the 

 studies of the reactions with different reagents were 

 limited to comparatively few of the reagents, and it is 

 obvious for reasons stated that the data recorded must 

 be accepted with reserve. 



NOTES ON THE ORCHIDS. 



The composite curve charts of Phaius and Miltonia 

 are very much alike, indicating closely related genera, 

 and quite different from those of Cymbidium and Cal- 

 anthe, which differ very markedly from each other and 

 also from Phaius and Miltonia. 







